I found this website that had a bunch of cool bio arts. the websight is particle-x.com. when you are there click Xbox 360 Bios Art Now Updated! to view the bio arts. you dont have to download anything.
1. you wil have to sign into xbox.com and and click your gamerpic or gamertag on top right.
2. now click edit profile.
3. scrole all the way down to were it says bio.
4. now go to particle-x.com and pic a bio you like.
5. go to the pic of the bio you like and highlight the letters under it
6. copy and paste it to your bio on xbox.com.
7. now save.
8. when you log in it will be there.
LOOK at my bio my gt: id0it4l0lz the 0s are zeros. Itz Bad As is banned sad face.