I removed KDE, emacs and a lot of applications i was never going to use, and still i couldn't get under 3gb, i got like 3.7gb, which doesn't really help me since my usb drive is supposedly 4gb but it only has 3.4gb (it sucks!!) actually i was about to try again and see what other packages could i discard when i saw your post, what do you recommend?

It'll be more helpful if you said exactly what you removed, i.e. define 'applications', otherwise it is much more difficult to make further suggestions as you might have already pulled them out.

Did you take out all of the following because if not then it is another 0.5Gb saving:

All of t series 250Mb
Qt 129Mb (it is separate from KDE)
Samba 125Mb

If you have already removed them then please give the full list of what you have removed.

Also give some ideas about how you intend to use this LiveUSB e.g. "Do you intend to run any server apps?", "Will you build software on it?" and so on. Also what are your must have applications that you cannot do without? If we know those it'll prevent us suggesting things for removal that are required for those apps to run.

I actually did it!! i could get it in 3.2gb, which gives me 200mb free in my usb xD is not much but at least i got i what i wanted, i actually removed kde, qt, samba, and a bunch of packages for wireless network cards, vim, emac, i can't remember all the packages though.
i want to thank everybody for your help. thank you very much. this is solved.

And what about the 415Mb (installed size) kernel-source package? You don't mention removing it. If you haven't, consider getting rid of it as well since that will take you below 3Gb, which was your original aim right?

yeah i actually did remove that package.