The iSlim 1320 has Linux support (Linux support: Enjoy online chatting in Linux.) according to the manufacturer .
Their website isn't helpful so it looks like u on u own as far as they are concerned.
I prefer to go with logitech since the later models (note the firmware bug in some early models) work out of the box.
See here http://linux-uvc.berlios.de/
and check the list. Some Genuis webcams are supported in UVC.
0458:505e Genius iSlim 330 Genius
0458:7055 Genius iSlim 2020AF Genius
0458:705d Genius iSlim 2000AF Genius
0458:706e Genius eFace 2025 Genius
0458:7071 Genius iSlim 1300 V2 Genius
From my experience it's best to check that u hardware is supported under Linux before u buy. Spending hours and hours looking for a fix is not is not something i want to do for a webcam.