If you'd like to hook up your iPhone or iTouch to a TV via composite video Apple sells a component AV cable to do so:
http://store.apple.com/us/product/MB128LL/B?fnode=MTY1NDAzOQ&mco=MjE1NTI2OA
The output is not hi def. The purpose of the cable is mostly to display movies or pictures.
Hi
I am waiting for the iPhone <--> displayport cable to be introduced.
Using your iPhone on the new 24"ACD would be cool, and then maybe a BT profile for the Apple Wireless KB as well.
That app patent awhile back showing an iphone like box sliding into an iMac-ish looking screen is adding up more and more I think.
Apple CD with minidport
iphone with minidport (or adapter for current iPhone plug)
Add in some BT KB support into the iPhone
A new more powerful iPhone in June 09 made possible by our friends from PA Semi, with batter battery life.
Running Snow Leopard's reduced footprint.
Neat stuff may be a coming soon...
Cheers
-wsn