iDialog

[VoltaicShock]

I downloaded iDialog (free) to test it out and it works great but the issue is that it's not iOS 4 ready. It doesn't support push and they won't be anytime soon. I e-mailed them asking about this. They are working to add multi-tasking support.

Are there any other options for Office Communicator besides iDialog? BB and Windows Phone have an app that works great.