I'm looking to pick up a blackberry to try out for a little bit, but I really don't want to part with my iPhone or my iPhone plan. Is there anyway I can have both a Blackberry Data plan and an iPhone data plan without messing with my service? Anyone do this on a weekly/daily basis? I know a lot of you buisness guys need it for work since Blackberrys networks are super secure. Edit: Sorry, I forgot to mentioned that I'd just like to switch my SIM between devices.