AVerMedia AVerTVHD Volar (A868R)
It is supported under Linux since kernel 2.6.27 
From lsusb: ID 07ca:a868 AVerMedia Technologies, Inc. Tested device was in a opaque metallic black plastic case.
AVerMedia's website (cached) shows a unit with a glossy translucent blue plastic case, and the high-resolution marketing image (cached) shows an IR receiver on the board, possibly necessitating the translucent case. Production versions of the A868 with the translucent case, however, do not include this IR receiver component, and have an internal board & component layout identical to the opaque black version pictured on this page.
Note also that while AVerMedia literature refers to this device as the 'A868R', production devices (both black and blue versions) are labeled as model: 'A868' (no 'R').
Making it work
Using a kernel > 2.6.27, required modules are:
No firmware is needed, the EZUSB chip appears to load via I2C from an EEPROM. Device must be connected to a USB 2.0 port to function.
(As of Dec 2008) This device seems to be universally on clearance and/or significantly marked down on both auction and common retailer's sites. Perhaps discontinued?