Hey I was actually thinking exactly the same thing the other day. Being so impressed that my friend's new car paired with his phone immediately and he could even browse through his address book on the screen of the car. I found http://www.gnokii.org/ and someone who ported it to the N800 (search the forums). My phone wasn't listed as compatible, so I haven't tried it. It should however be possible to have a less rich featureset then gnokii and work with any phone with bluetooth. Haven't found such a thing yet however.