guvcview is a video viewer and capture software for the linux UVC driver. It is based in luvcview (http://mxhaard.free.fr), but all controls are done with GTK, allowing for a more user friendly GUI.
Java access to USB, currently using kernel 2.4 Linux-USB support. There is a "core" API for accessing USB devices, and simple tools including a USB viewer in Swing. Applications are being developed separately, including digital camera support.