After last week's rumors, Skype's iPhone client has been confirmed.  The VoIP software, which will be released on Tuesday March 31st, will be a free download and allow users to make free Skype-to-Skype calls over WiFi networks.  Alternatively, calls to landlines will cost 2.1 cents per minute.

What won't be possible is VoIP over 3G.  According to Skype's chief operating officer, Scott Durchslag, this is a limitation of Apple's App Store terms of service.  Neither AT&T nor Apple answered a request for a comment on the Skype app.

iPod touch owners will also be able to download and use the software, though they'll need to buy a microphone accessory since the PMP doesn't have one integrated.  After iPhone OS 3.0 is released, however, 2nd-gen iPod touch users should be able to use the PMP's newly-unlocked Bluetooth with hands-free headsets.

[via GigaOM]