Jcam captures and saves JPEGs and Video from your webcam, manually or automatically. It works on Linux and Windows, for cameras with drivers compatible with v4l or vfw. It uses Java(1.3.1), Swing and Blackdown/Sun JMF2.1.1 respectively.
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.