Whether it's clothing, video games, or music, underground is in. It's skateboarding, street racing, and street life in hip-hop mania. But where do you look for profits?

If you haven't noticed, clothing retailer Urban Outfitters (NASDAQ:URBN) has been hitting high after high. Ditto for Pacific Sunwear (NASDAQ:PSUN), which LouAnn Lofton has examined for hipness.

Video games? Activision (NASDAQ:ATVI) is all thugged out with its fifth iteration of the famed Tony Hawk skateboarding series -- Tony Hawk: Underground (THUG). And with a soundtrack powered by West Coast rappers such as Snoop Dogg, Jay-O Felony, and Warren G, Activision has gamers hitting the streets in True Crime: Streets of L.A.

Further, in a movement largely inspired by Vivendi (NYSE:V) Universal's The Fast and the Furious and 2 Fast 2 Furious movies, illegal street racing has also hit the video game scene in a big way.

Capitalizing on the popularity of 2 Fast 2 Furious, Electronic Arts (NASDAQ:ERTS) released street racer Need for Speed: Underground last week. The certain blockbuster features a plethora of upgradeable parts to go with some of the world's most modified cars, including the Nissan Skyline and my personal dream car, the Toyota Supra.

Similarly, Take-Two Interactive Software (NASDAQ:TTWO) was right there on the underground racing scene with its recent smash hit, Midnight Club 2. Atari's (NASDAQ:ATAR) Test Drive followed the success of the first movie.

While movies influence video-game popularity, games in turn affect the music industry. A couple of years ago, EA Sports released Madden 2002. And who was that on the opening track? Rawkus Records' Mos Def.

Nowadays, Madden -- which has become so relevant that it is in the football hall of fame -- features Blink 182, The Roots, Adema, and Jet. No doubt, video games have become a launchpad for musicians, distributing music to millions of people worldwide.

This is a hip-hop era where Christopher Wallace becomes Notorious B.I.G. (R.I.P.), Shawn Carter is Jay-Z, and Marshall Mathers makes a great movie (8 Mile). The things that have ticked off more than a few people over the years have become a cash cow for those who will listen.

From clothing to video games to the music and hip-hop culture driving all of it, underground has hit the mainstream in a big way. If you're willing to listen to the music, certain retailers and video-game publishers merit further examination.

Who is the king of video games? Let us know on the Activision and Electronic Arts discussion boards.

Jeff Hwang can be reached at JHwang@fool.com.