A very, very small (and cheap!) USB Bluetooth dongle, which works out of the box in Linux.
0a12:0001 Cambridge Silicon Radio, Ltd Bluetooth Dongle (HCI mode)
A USB audio device, works fine in Linux.
Bus 001 Device 011: ID 1130:f211 Tenx Technology, Inc.
A crappy (but tiny) webcam I bought a long time ago.