i can't take credit for this but here:
http://ioconnections.com/productdetail.aspx?id=545
it's a thin client from ioconnections. you want to call them because they need to create a custom thin client that has a video card that can handle output to a television. it's real real small and can be controlled remotely w/the sw ioconnections includes. it can also connect to your network, so you can download slide shows or whatever from your file server if you want. then you just have to, well, do what you want.
we paid $660 for it, and their customer service was EXCELLENT. can't say enough good things about them.
the only thing you have to do on your end is purchase a television (our's is a 42" plasma Daewoo) that can handle output from a computer.