Version 4.2 of aTV Flash (http://firecore.com/atvflash) — an US$49.95 USB flash drive that inserts into the Apple TV and will upgrade it to do various kinds of new things — has been released. 

This version — a free update to registered users of version 4.0 — brings a certified Last.fm app to the Apple TV. It allows you to experience your favorite music and includes support for streaming Last.fm radio, artist bios, artist artwork and scrobbling recent plays back to Last.fm.

As always, aTV Flash includes support for additional media formats that are not typically supported by the AppleTV. These formats included DivX, Xvid, AVI, WMV, VIDEO TS (DVD files) and many more. Additionally it adds a fully integrated WebKit based web browser, and the ability to expand the storage capacity through the use of an external USB hard drive.