arn,
just a bit of info. i used to visit a site that was designed around smartphones, so obviously they had a mobile version too. i think this is what they did:
main site: everything as normal
mobile.mainsite.com: seperate installation of vB but accessing the same db. so it's always updated - but you can disable smilies and change other prefs without ruining main site.
just a headsup of how someone else did it 🙂