Did I mention that it's National Hamburger Month! Let's celebrate!

But what are we celebrating? Is it the mating of bread and beef by the Mongol Tartars? Or is it the sandwich made in Hamburg Germany in 1891 of two slices of bread, ground sausage beef, mustard, a pickle or two, and a fried egg? Yeah, right!

Unfortunately, precisely who, sometime just after 1900, invented today's bun-and-beef delight is not clear. What is clear is that, 100 years later, business is booming. Here are some companies to discuss around the barbie this weekend.

McDonald's (NYSE:MCD) is targeting long-term annual revenue growth of 3%-5%, growth in operating income of 6%-7%, and a return on invested capital "in the high teens." McDonald's is a great brand and a great company, but given the growth rates and a stock trading at 20 times earnings, don't expect another 45% rise over the next 52 weeks.

Wendy's (NYSE:WEN) is growing rapidly and trades at a modest 17 times 2004 earnings -- and roughly 14 times 2005 earnings. That's a very reasonable price for a geographically diversified company with a name you know.

Red Robin Gourmet Burgers (NASDAQ:RRGB) is a casual dining chain with over 230 locations. Revenue was up a whopping 26% last quarter, and net income scored a 49% gain. Based on the company's conservative guidance, the stock trades at a modest 21 times 2004 earnings and 18 times 2005 earnings. Not too shabby.

Red Robin may be upper scale, but there is something about having a hot burger delivered to your car by a skating attendant that makes Sonic (NASDAQ:SONC) special. While it trades at 22 times trailing earnings, its rapid growth should whittle that multiple down to a not-quite-so-rich 17 times earnings in 2005.

Checkers (NASDAQ:CHKR), meanwhile, has earned its way through tax-loss carry-forwards and is now a taxpayer. Hurray! But, even with strong same-store sales, earnings will come in below 2003 levels -- all because of taxes. Those taking a longer-term view will notice that, based on analyst estimates for 2005, the stock trades at a bargain 11 times earnings.

Finally, it's not all roses in burgerland. Back Yard Burgers (NASDAQ:BYBI) recently saw a multi-brand restaurant deal with KFC parent Yum! Brands (NYSE:YUM) fall through. As a result, Back Yard's 9.4% jump in same store sales in the latest quarter wasn't enough to prevent the stock from being down over the last 52 weeks.

So, by all means, celebrate the paradigm-shifting marriage of beef and bun, but know that not everyone is doing likewise. Beef is taboo for Hindus and frowned upon by many Buddhists in East Asia. For investors, there should be very few frowns if analyst's 2005 estimates prove out. Now that's something to celebrate!

Here is the trivia W.D. will be taking to the cookout this weekend. Henry Ford invented the charcoal briquette in 1920 with the help of Thomas Edison using wood scraps and sawdust from the car factory floor. Yum! E.G. Kingsford bought the invention.

Want to discuss the Art of Fun(ky) BBQ or Recipes and Cooking? Or, how about talking about McDonald's or Red Robin Gourmet Burgers? Join in our discussion boards.

Fool contributor W.D. Crotty does own stocks in McDonald's and Checkers.