The PlayStation Eye is a webcam device by Sony Computer Entertainment for the PlayStation 3 video game console. It is the successor to the EyeToy for the PlayStation 2. In case you have one floating around that you do not use for gaming, why not trying to use it as a webcam? You can find them cheap everywhere on ebay, ricardo.ch, leboncoin.fr
It is not anymore difficult to make this webcam work under Windows (Sony sell this camera since 2007), as there is good and stable drivers now available. I did test the webcam under Windows 7 64 bits and Skype. It work great as long as there is enough lights in the room.Note that the multi-directional microphone is quite exceptional of quality (The PS3 use it for voice location tracking, echo cancellation, and background noise suppression.)
Windows XP, Windows Vista, Windows 7
The CL-Eye Platform Driver recommended for general users provides audio/video functionality with a single CL/PS3-Eye camera supported in a wide range of native and web applications that use Microsoft Windows DirectShow Framework (Skype, YouTube, Adobe Flash, AIM, MSN Messenger).
A working driver for MacOS can be downloaded from http://webcam-osx.sourceforge.net/
Starting with Linux kernel 2.6.29, just plug your PlayStation Eye in a free USB port and enjoy. Tested under OpenSuse 10.2