Can I put my iPhone sim card into a Blackberry and have BBM?

My iPhone 4 is very very slow and I'm not available for an upgrade until November, so I want to buy a cheap Blackberry I found on eBay. I was just wondering what would happen with BBM if I did this. Would I be able to use it, or not? And would I have to pay?

You ONLY access BBM when the sim card is PHYSICALLY in the Blackberry even via Wi-Fi

As this was an Iphone contract you would still get whatever allowances you have under contract, but would have to pay £5.00 PM on top to get BBM as the IP4 contract did not include it

You should try to restore the iPhone to see if that helps speed it up, though most people don't complain about the iPhone 4's speed.

Would be better than going to a BlackBerry. As far as what would happen the 1st answerer explained.