You can just click 'Showcase' and then type something into the 'Gamercard Search' spot. There's more than just gaming ones, I'm a Celtics fan and I snagged a nice Celtics sig as well. They just give you links to copy and then you just edit your GT into the link where it says and you're all set. If you register and stuff you can get your gamertag validated by doing the steps they give you and you can create your own sigs like mine. I tried but failed miserably :P Have fun.