I have an iPhone 3gs as my main phone and I recently bought a blackberry tour with no plan. I think touchscreens are difficult to type with so I planned on just taking the SIM card out of my iPhone and putting it in the blackberry for messaging. The problem I'm running into is I'm not sure if the iPhones SIM card will work in the blackberry. Does anyone know if there will be a compatibility problem between the two?
Not in terms of data plan. You'll have to sign up for the blackberry internet service.
But for messaging it ought to work. Don't take my word for it though - since you already got the blackberry why don't you try it out?
If you are in the US you might want to make sure the phone is compatible with the carriers frequencies. I know AT&T uses different frequences than say T-Mobile/Verizon (which is a pain).
Other than that it shouldn't be a problem
And in Canada there are 3 frequencies.
As long as the frequency is right, and the blackberry is unlocked, it should work.