If you still haven't had your morning caffeine, these figures might just wake you up. According to the NPD Group, sales of iced coffee at quick-serve (aka fast-food) venues were up 38% from March 2007 to March 2008, after rising 37% the year before. Talk about an energy boost!

All of a sudden, I see more clearly why McDonald's (NYSE:MCD) -- and, with less fanfare, Burger King (NYSE:BKC) -- have introduced coffee offerings in recent years. There's big money to be made in carving out a slice of market share from iced java purveyors such as Starbucks (NASDAQ:SBUX). The bigger picture is even more tantalizing than those numbers suggest: While 52% of American adults drink coffee daily, imbibing some 400 million cups per day, the total for iced coffee is just 640 million cups -- per year! (Can you say "room for growth"?)

That's good news for investors in fast-food establishments, and yet another challenge for the recently languishing Starbucks. (Trust me -- I'm a shareholder.) It also seems to spell trouble for drinkmeisters Coca-Cola (NYSE:KO) and PepsiCo (NYSE:PEP), since much of the growth in specialty coffee sales seems to come at soft drinks' expense. Between July 2007 and July 2008, sodas provided 41% of beverage sales, down from 46% in 2003. Iced tea is also a booming beverage -- which may explain the sudden arrival of "sweet tea" on certain McDonald's menus.

A sip of stock strategies
Consumer consumption trends can guide us to great investments, especially if we monitor how well different companies respond to them. As my colleague Alyce Lomax recently showed, companies that fail to meet consumers' desires -- like American automakers, who stubbornly pushed inefficient vehicles even as gas prices rose -- will suffer. But companies that can stay ahead of the latest trends are more likely to cash in. So are their investors.

If you're looking for companies that are not too big, seem undervalued to our analysts, and that have a heck of a lot of room to grow, test-drive our Motley Fool Hidden Gems newsletter service free for 30 days.

Starbucks and Coca-Cola are Inside Value selections. Starbucks is also a Stock Advisor pick and a Motley Fool holding. Try any of our investing newsletter services free for 30 days.

Longtime Fool contributor Selena Maranjian owns shares of Starbucks, McDonald's, PepsiCo, and Coca-Cola. The Motley Fool is Fools writing for Fools.