aircard or other options?

I'm a Mac wannabe at the moment. When I replace my HP notebook I'd like to switch over to a Macbook or maybe a MBP. My question relates to internet connectivity. I know if I'm around a wifi provider I can use that. I currently use a Sprint aircard. My questions are 1. will the Sprint aircard work with whatever Mac notebook I might get?, 2. can I use my iPhone with whatever Mac notebook to do what the Sprint card is currently doing for me? and 2a. if the answer to 2 is yes would that be included in my current monthly fee to ATT that includes unlimited data? Thanks for any and all input.

1. ask sprint - they'll have the latest compatibility info
2. indirectly (using mail and safari on the iphone itself and then syncing)
2a. yes, that IS the data plan