It looks like a cell phone and PDA company, HTC, is trying to port Skype to their smart phone, so you could make calls whenever you are within a wifi hotspot. The author mentions that with the 3G network, you wouldn't even need to be in a typical hotspot - you could do it from anywhere.

That would be great. Free calls from your cell phone. I've used Skype for the Pocket PC, and it works fairly well (other than the locking problem they had with the Dell Axims a while ago). 

I'm still waiting for someone to develop a way to seemlessly switch networks. If I could initiate a call on my phone, get in a hotspot, and have it automatically transfer to WiFi, that would be awesome. Add in the ability to switch from calling a land line phone to calling thier Skype device, and now we're talking!