If you already own a BlackBerry and want to use it for email and browsing rather than calls, it's going to be hard to beat this deal: Crazy John's is offering a prepaid BlackBerry SIM for $29, which includes six months of unlimited email and browsing via the BlackBerry browser.
We've commented before that one of the challenges with a BlackBerry is that most of the options which include BlackBerry Internet Service -- which makes the magic of BlackBerry email happen -- are only available on postpaid contracts. As such, this a welcome addition.
Once the six months are up, you can also top up the pack for $24.95 for another six months. I use a similar deal from Optus, but that doesn't seem to be actively promoted anymore. If you do have a BlackBerry sitting around, this is a dead cheap way of reactivating it as a browsing device.