Blackberry as wireless data connection

Does anyone have any experience using a black berry via USB cable as a wireless modem for a laptop?

If so about what speed were you able to obtain and did it compare to the PCMIA wireless cards

I’m in line to get my users some sort of wireless solution for remote access through citrix, and most of them already carry a cell phone. I’ve heard of using the blackberry as a data connection just don’t have any experience using it or any knowledge of expectations beyond what the sales guys has told me.

Any feed back would be great!! Thanks!!