IM app that BB and Iphone users can use to communicate

[Gamer]

Hey everyone, thanks for the suggestions. We've installed and been using Whatsapp since Friday and it's working very well indeed.
Yes, it costs only $2.00 per year, AFTER the first year. Mine says it expires on 19 August 2011. That's really for nothing.
The iPhone app only costs $1.00 (if you're not jailbroken). I let iPhone mates all over the world know and now we're messaging from Sydney to Rio and to my wife around the corner

Thanks all.

 

[diabolus]

There's also http://pingchat.com/

Works between Android, Apple and Blackberry.

 

[Mr Feesh]

It kills the battery on my iphone 3g, 2 hrs of whats app can take my fully charged phone to flat

weird my boet manages to easily make it through the day with the app running no stop