Unlock your Galaxy Tab! Apparently its quite easy for the brave that don't mind rooting and fiddling with their /efs folder.
http://forum.xda-developers.com/showthread.php?t=843323

I've read reports in this thread of Bell Canada Tabs working with Rogers SIMS! This would be a great tool for traveling, or for carrier freedom in general.

But am I right in assuming that 3G speeds will only be possible with carriers that use the same frequencies? I know nothing of cellular networks.. or women...