Thanks for the responses all.
http://www.gromaudio.com/store/ipod_adapters/grom-i2-maz.html
I just bought the GROM iPod Adapter from their site. It says that it charges both the iPhone 3G & iPod Touch 2g, so that should work for my 2g Touch.
How complicated is installation? How do I get to...
I've got an '04 Mazda3. 6-cd changer and no tape deck.
What would be the cheapest iPod (or 3.5mm) input that I could buy?
What control would switch it on?