Hardware for Homebrew Motion Capture?

goruka asks: "We are a small garage game development and 3D animation group, and as such, we try to develop by reducing costs as much as we can. Recently, it came to our mind that we could setup and develop a home-brew motion capture system by using three consumer USB web-cams to motion track bright objects attached to the body. However, we don't know which web-cam models can: capture at a decent frame rate (25fps) and resolution; are supported and easily programmed under GNU/Linux, since we'd like to later release our software as open source; and lastly, won't cost us a fortune. What are your experiences with such devices?"