Mobility
In response to Tara’s PDA question.
I agree with Warren: get a Bluetooth-enabled phone, such as the Sony Ericsson T610. It’s excellent.
I use a tiered ‘mobility’ system:
Tier 1 is the base station, which is my G4. I use iCal and Address Book.app on it. All data entry and long-term calendaring /corrections/should be done here. The data stored here should be held as “true”, over all systems.
Tier 2 is the work station, which is my iBook. I use iCal and Address Book.app on it. I do almost all of my data entry here, and clean it up on the base station. The iBook is a mobile workstation, so I can lug it anywhere, change or create stuff, and eventually sync that data with the base station.