Or get a Pioneer AVIC-F900BT, hehe
Outgoing model right now, so should be cheap to pick up, current online prices around £550.
If you are computer savvy, then you could avoid the ridiculous prices Pioneer charge for map upgrades and do them yourself (Pioneer charge £150 for upgrade)
For your money you get a CD-Tuner with sat-nav and iPod & SD card connectivity, option to add a reversing camera, Bluetooth handsfree connectivity, which allows you to transfer your mobiles phonebook to the unit too.
I got one and am more than happy with it