Assuming the Macbook Pro has no SIM slot for wireless 3G (?), can anyone recommend a good USB external wireless modem which works well with Macs in Thailand? And the best data SIM provider for Pattaya area? Thanks.

I guess CAT CDMA doesn't work in Pattaya. I'd try and see if Hutch offers anything there, and maybe True 3G is there too? Any USB modem will work... it's the provider that is the issue. All the phone companies offer EDGE but despite what some people may say it can't compare to either CAT CDMA or True 3G in any way.