yeah thats what i was thinking megs as in megabytes but its on a 4 gig flash drive with 3 and a half gigs left its the only thing on there also it works on other computers if i take my flashdrive out and put in my school campus computers it works on those
I think you're confusing RAM with storage (disk) space. Think of RAM as the table upon which you can lay out your toys/projects/whatever; more RAM means more projects and games can be open at once. Disk is your closet, where you keep things you're not playing with and storing for long term; more disk means more storage for other stuff you're not working on right now.
The error message sounds like (though I don't know for sure) you need more RAM, so the size of the flash drive upon which you have Tremulous installed makes no difference. Try closing programs on the computer that you're not actively using (IM programs, Word, Internet Exploder/Firefox/etc).