rooting shouldnt require a computer, download the file labeled update.zip(aka. droid-root.zip) and put it on the main level of your sdcard, you can use Astro to download it right on your phone and move it to the main part of the sdcard
Important Files | Sholes
then you can just do steps 3 and 4 and you will be rooted
3. Reboot into recovery mode by holding down the “X” button on the physical keyboard the whole time during boot until you come a /!\ symbol. Then, press the volume up + camera buttons to bring up the menu.
4. Choose the option “apply sdcard:update.zip”. Wait for it to finish, reboot, and voila you’re rooted.
***HOWEVER***
if you are going to root your phone, i STRONGLY recommend that you do what is detailed on this page
Installation | Sholes
it will set you up with adb working and with sprecovery, which will allow you to make nandroid backups, which are basically like restore points for android
so you dont need a computer to be rooted but i would strongly recommend doing everything listed on
Installation | Sholes which does require a computer