i have used lots of phones as modems, and among the units that i've used, nokias and the sony-ericssons are the easiest to use and to configure (N6630, N6680, N70, N91, SEk750i, SEK800, SEP900, N9500, N9300).

i would agree with nico, stay away from motorolas. ang hirap and mukhang imposibleng gawing modem.