VOIP on the iPhone

[tipling]

Two questions.

1. What, if any, VOIP applications are available on the iPhone now?
2. Has anybody figured out a way to get the iPhone to work on T-Mobile Hotspot @home?

[dlmart2]

I recently read in Businessweek that a startup company is in the process of developing a VOIP like app that takes advantage of hot spots to make international calls. Doesn't directly answer your question, but its related...

Two questions.

1. What, if any, VOIP applications are available on the iPhone now?
2. Has anybody figured out a way to get the iPhone to work on T-Mobile Hotspot @home?