PIC18F4550 microcontroller has USB module built in. This allows using USB interface without additional interface chips and drivers. Evan has developed pretty simple PIC18F4550 prototyping board which is capable to download software via USB without need of other external programmer adapter.

Board can easily be adapted for various PIC USB interfacing projects such as HID or virtual COM port applications. PIC board is quite compact, but it has all pins available for interfacing. You may also want to grab a PIC USB Bootloader in order to test USB run.[via]