there is this object for gem which allows you to open .obj-files. now how can i write .obj files or where can i get more of them?
can anybody help?

export them from a 3d program like blender

ok thank you!

http://www-ui.is.s.u-tokyo.ac.jp/~takeo/teddy/teddy.htm
Wow dude! Just found this website from the lowend3d forum.
This is an amazing java applet that allows you to sketch and export .obj files extremely easily.
Blender is the bomb for serious stuff, but this program gives you instant gratification and that total psycho outsider aesthetic.
edit: this for windows. i tested one object and it works.

I have grabbed many .obj from turbosquid.com