Ten bucks says you can't inventory your closet in much detail -- clothes, shoes, maybe a baseball bat or two. But what's lurking in the dark corners of your personal space? Even worse, do you know how long it's been hiding there?

We all have a few long-forgotten collectibles gathering dust in our closets (right next to the skeletons). Some of these odds and ends may not be so scary, though. In fact, they could be quite valuable. Rummaging through the stock market's closet isn't so different -- investors may be quite surprised to find what's there, and even more surprised to discover how much it's worth.

Hiding in dark corners
Imagine it's 1982 and you've received a gift of a few shares of Wal-Mart (NYSE:WMT) from your Uncle Joe. You file it away appropriately (where you'll never find it, of course). Flash forward 25 years: You're cleaning out the closet, and you stumble across those shares. If Uncle Joe had bought you $1,000 worth of Wal-Mart stock at the time, you'd now be sitting on a plump $146,000. Not a shabby reward for being forgetful and untidy, eh?

There are literally hundreds of companies out there like Wal-Mart -- familiar, well-managed organizations that don't exactly set investors drooling with visions of great wealth. That's too bad -- some of these drab closet-dwellers pack a powerful punch. Consider some other companies lurking in dark corners, but generating amazing returns:

Who would've thought that sweaty, smelly pieces of rubber and synthetic leather could be transformed into a fashion statement? Nike has done an incredible job of taking shoes from a commodity item to a premium product, rewarding long-term investors along the way. Since going public in 1987, Nike has returned more than 6,400%, or roughly 23% annually, for shareholders. Younger competitors Skechers USA (NYSE:SKX), Deckers Outdoor (NASDAQ:DECK), and Crocs (NASDAQ:CROX) are all kicking for their turn as a world footwear giant -- and to date all three have done a pretty good job of making fashionable footwear a rewarding part of any portfolio.

Dick's Sporting Goods
From tennis to lacrosse to wakeboarding, Dick's carries everything that a sports enthusiast could possibly fit in a closet. The retailer of sporting equipment and clothing has been posting solid growth for several years, rewarding shareholders with a 595% gain since going public in 2002. Smaller competitor Hibbet Sports (NASDAQ:HIBB) has seen similar success and hopes to carve out its own profitable corner of the sporting goods market in underserved, more rural areas.

Rather than manufacture its own merchandise, Cherokee licenses branded clothing to major retailers such as Target. Simply licensing popular brands such as Cherokee and Sideout keeps margins sky-high, generating plenty of cash for the company. This closet-dweller has kept shareholders happy, too, returning a whopping 9,000% since going public in 1995.

And that's because licensing can be a pretty profitable business model.

Similar company Iconix Brand Group (NASDAQ:ICON) owns and licenses brands such as Joe Boxer, Ocean Pacific, and London Fog to major retailers. The company has been on a roll the past three years, picking up new brands such as Mossimo and Rocawear and returning investors a monstrous 744% in that period.

Come out of the closet
Nike, Dick's, and Cherokee show that great things can come from commonplace sources. Each has a similar story -- they started as small and little-known companies, led by founders who focused on steadily dominating a product niche with wide consumer appeal. Nothing too flashy or fancy; just steady growth on the top and bottom line, thanks to efficient management. And that's been the recipe for success for some of the other companies mentioned in this article as well.

While some investors spend hours scouring all sorts of industries for great stocks, many know they only need to go as far as their closet to find some killer companies. Unafraid of facing the boogeyman, Motley Fool Hidden Gems lead analysts Tom Gardner and Bill Mann dig through musty closets to find monster stocks with similar traits, long forgotten or overlooked by many investors. Click here for a free 30-day trial, and see what surprising winners they've come across.

This article was originally published on Apr. 20, 2007. It has been updated.

Fool contributor Dave Mock is more worried about what lurks in the back seat of his car than his closet. He owns no shares of companies mention in this article. The longtime Fool is the author of The Qualcomm Equation. Wal-Mart is an Inside Value recommendation. The Motley Fool's disclosure policy keeps a flashlight under the bed, just in case.