for personal use on holidays, the PDA is best. It's small, light,
and you can carry it during the day.

Having both a Pocket PC, a Palm, and a PDA/phone, the Palm
is slightly better. Generally speaking, the Palm battery lasts
longer and the apps are slightly better.

You'll need to have Metro (worldwide subway maps and direction
finder), the airline schedules for, say United, and if you travel
by rail, the railroad schedules.

For me, the United schedules are better on a Palm than a PocketPC.
The palm displays all combinations, the PocketPC does not -at least
for the cities I travel to.