If you have the power to design/create your own head unit, what features would you like included?

Currently, standard features include:
- DVD
- Touch Screen LCD
- GPS
- TV Tuner
- Bluetooth
- MP3, USB, iphone integration

My wish list would include:
- on-board internet access to check emails, surf the web
- Compass, temperature
- TPMS
- photo slideshow

Just wondering what other nice features would make sense for a future HU.