Provided you have the ability to tether to a cell phone at a reasonable cost, the N810 should be right up your alley. Go to www.maemo.org and check out the apps available. There are probably more than a few that should help sway your decision.

I don't use mine at all anymore, tethering in Canada is like winning the reverse lottery (you pay them $10,000 a month) and I drank the kool-aid and got an iPhone which does the trick for me.