Java for the NXT: leJOS NXJ alpha 0.2 available now
The guys from leJOS have released the alpha 0.2 version of leJOS NXJ.
leJOS NXJ enables you to program and run Java programs on the NXT; it is a full firmware replacement that works for Windows and Linux.
The new release now contains support for Bluetooth (preliminary ), I2C (Ultrasonic sensor) and sound.
Try it out!