If you want to a cool Polo Shirt? The cool Business Polo($25) features the Big Richard Logo. The red logo says: “I’m in charge here.” It says, “I’m passionate about what I’m doing.” It says, “I’m the man, and I know it.” And you are the man. Available in red and orange.
The thinkgeek's Electronic Rock Guitar Shirt($30) includes its own mini amplifier and special magnetic pick on shirt, you just cranked the volume to 11 and started to rock. "it is a real musical instrument that allows you to play your favorite songs and sound great doing it. All major chords are recorded from a real electric guitar, and the included magnetic pick allows you to strum just like you would a real guitar. The included mini amp clips to your belt and gets plenty loud with great sounding amplification circuitry."
The Lego Baseplate Shirt($18) is a Brick Construction Shirt with the black baseplate on the front, so you can stuff on it - Lego murals, a Lego spaceship, chunky boobs, whatever floats your boat. From thinkgeek shop.