lol.... ofillusion... it tooke me a month to learn to do transperencies BECAUSE NO ONE TEACHES IT!

but... i guess since i know how it feels, ill tell u....
if u are using GIMP 2.0
when it is open, go to files, click open dialog/layers.
then add an alpha channel to ur background. when u erase stuff from ur back ground, it will become transparent... thats basically it
GL!

also fogle you can use "color to alpha" its easier to turn the background to transparent

thats also a nice way to do it =) ty for helping out that dude =)