PCS Wireless Internet -- Which service? Which phone? Data card compatible?

[TerryMcK]

I'm getting started on the search for national wireless internet access beyond simple hot spots. I'm looking at (1) Sprint, ATT, T-Mobile, Verizon, etc...(2) trying to decide which has best coverage, (3) whether or not the data card works with Mac oSX and (4) which is better: the data card or using Bluetooth to link my Mac with a cell phone connection.

I'd appreciate hearing any of your experience and ideas with these issues.

Terry