Belkin has just announced their new Tunedeck accessory for the iPod Nano. The Tunedeck combines a cassette adapter with a a swiveling iPod Nano mount, so you can just plug it into your cassette deck, and the Nano will sit nicely at eye-level with your stereo. The Tunedeck will also charge your iPod when connected through your cigarette lighter. MSRP is $49.99.
Not sure how this will work on cassette decks that lower the tape into the deck, like the one in my car, but from the looks of the picture on Belkin’s site, I think it should work.