The life of a college student is a tough one. Going to bed at 5:00 (that's a.m.), getting up before the cafeteria closes for lunch, and balancing class time with study time, internships, work, athletics, volunteer functions, and a social life make for a busy day for the typical college student.

In addition to being consumed by all of these pressures, students are also doing their share of consuming. A look at what they're buying can reveal remarkable investment opportunities.

A line from the now cult-classic Napoleon Dynamite, "It's a time machine, Napoleon. We bought it online," highlights where many of today's youth are going to spend money -- the Internet. Whether it's Patagonia sweaters or shoes from Zappos.com, there's a seemingly endless array of goods being purchased online by students. One of the many companies poised to benefit from this revolution in retailing is Motley Fool Stock Advisor pick FedEx (NYSE:FDX).

But the focus of this article is not simply on those brands that benefit from youth trends. In particular, I'm interested in the enterprises that are shaping and influencing the buying patterns of college students. Based on my time as an undergraduate student and a current graduate student, here are my top three student-focused businesses and investment opportunities: Starbucks (NASDAQ:SBUX), Apple Computer (NASDAQ:AAPL), and Abercrombie & Fitch (NYSE:ANF).

The attire
In my opinion, no other company reflects the attitudes and defines the wants of college students better than Abercrombie & Fitch. Fellow Fool Stephen Simpson recently discussed how youths have always partly been driven by rebellious attitudes toward adults -- in particular, their parents -- and A&F captures that spirit in its clothing. But even more, any company worth its salt also has the power to define consumers' wants, and A&F is no exception. Torn-up hats, hole-filled jeans, and silly baby-doll tees with borderline-obscene messages written on them all sound like the stuff that gets passed on to Goodwill, right? Unless you're over 70, it should come as no surprise to you. This is exactly the kind of must-have product that students' hard-earned dollars, or their parents', is going toward, and A&F is right there cashing in.

Over the past three years, this stock has tripled in value, and the latest quarter showed a company still going strong. Its collection of A&F, Hollister, and REUHL turned out 35% top-line growth, while management continued to strengthen its profitability. And because of the combination of double-digit sales growth and strong margins, analysts are projecting the enterprise to earn $4.11 per share next fiscal year, or 17.7% more than this year's earnings estimate. A forward P/E of around 15 is a reasonable price for this kind of growth.

If you're looking for another idea, a runner-up that's rapidly gaining momentum among students is Urban Outfitters (NASDAQ:URBN). This company's target audience is from 18 to 30 years of age, so its product offerings share some resemblance to A&F's REUHL line. But have no fear, prospective buyers -- there's plenty of the wild in these threads that should continue leading to strong growth in the quarters ahead. As its name suggests, Urban is geared a little bit more toward urban lifestyles than, perhaps, A&F. What it lacks in raw sex appeal, which is A&F's strong suit, it more than makes up for in edge.

The music
What would America's youth be without its music? Over the decades, Elvis, the Beatles, Madonna, Gwen Stefani -- none would be who they are today without the following they garnered on college campuses around the country in their day. And no other company found a better way to bring the song to the student than Apple Computer. How so? This is a rhetorical question, of course, because if you don't know, then it's unlikely you're actually reading this article, have an Internet hookup, or have any connection to the outside world. How about 15,000 songs in your pocket? That's exactly the kind of resource available at our fingertips in Apple's top-of-the-line iPod digital music player. And while iPod units are flying off the rack with FY 2005 unit growth of 409% that followed FY 2004 unit growth of 370%, its iTunes Music Store continues to climb the charts of the most-visited websites.

Apple's music dominance is leading to growth in other areas, including its desktops division -- once a dog of the industry. Apple's desktop units saw 55% growth in FY 2005, a major improvement from an 8% decrease in unit sales in FY 2004. One product contributing to this rebirth is the super-cool iMac G5. The sleek space-saving design is perfect for the small desks typically found in college dorm rooms. This is exactly the reason why I purchased the product. Combine its cutting-edge design with striking good looks, together with its ease of use and ability to seamlessly integrate gadgets like iPod or a digital camera, and it delivers students a powerful package capable of tackling their chores in style.

In the opening line of the Business Strategy section of Apple's recent annual filing, it reads, "The Company is committed to bringing the best personal computing and music experience to students." I'll stop there. This, in a nutshell, sums up why Apple made my Top 3 most-influential companies among America's collegiate youth -- the company is focused on them.

Microsoft (NASDAQ:MSFT) Office is a key part of any student's life, and increasingly so is its Xbox 360, but Apple is the clear winner among our technophile youth. And when you consider that as of FY 2005, it currently operates only 116 retail stores, it becomes evident that Apple has ample growth opportunities remaining by simply expanding to a college campus near you.

The juice
It might be said that the bloodstream of the typical male student is one part coffee, one part beer, and one part protein + creatine (I can't speak for the typical female student, since I am not one myself). Body-building shakes aside, it's hard to pick any brand over the apparent oxygen supply of America's youth, Inside Value pick Anheuser-Busch's (NYSE:BUD) Budweiser beer. On college campuses, there are as many beer goggles as there are sunglasses and contact lenses. And what frat party is complete without Frank the Tank? Alcohol certainly has a formidable influence on the life of many college students, it is true. And perhaps I am naive in thinking that it is Starbucks, even more than Anheuser-Busch, that better represents the collective student body of campuses across the country.

From its DoubleShot espresso drinks -- for that jolt of caffeine on the fly -- to its campus-centered coffee shops that offer students a place to study, surf the Web, chat with friends, and slake their caffeine thirst all at the same time, Starbucks has developed a winning strategy. In its newly released 10-K filing, the company said this of its retail store locations: "Its stores are located in or near a variety of settings, including downtown and suburban retail centers, office buildings, and university campuses." That last one is one reason this company makes my Top 3 list.

This strategy has led to big bucks for the company and supersized returns for its shareholders. Starbucks has been kicking butt and taking numbers among other investments for years, but even in the latest fiscal year, it still managed 20.7% and 29.8% revenue and earnings-per-share growth, respectively. There's no slowing down going into FY 2006, with plans to open an additional 1,800 stores after opening 1,600-plus in 2005. Its stock continues to bear a premium price tag at roughly 37 times next year's estimated earnings, but for as long as I've followed the company, it's been expensive. Like the two previously mentioned picks, investors have to be willing to pay up for quality, and a Starbucks investment is no exception.

Making noise
There are plenty of other brands out there vying for student dollars. But you need look no further than Starbucks, Apple, and Abercrombie & Fitch for those investment opportunities that not only reflect the youthful trends on college campuses but are also shaping those patterns -- a combination that should lead to further market-beating returns.

FedEx is a Stock Advisor pick. Anheuser-Busch is an Inside Value pick. For a 30-day free trial, click here andhere, respectively.

Fool contributor Jeremy MacNealy owns shares in FedEx and Microsoft but not in any of the other companies mentioned. The Fool has an ironclad disclosure policy .