Skyple may be a good app. on an iPhone. But where it genuinely has the potential to be a killer app. is on the iPod Touch. Get one of those (the 8gb model is something like $230) and a set of earphones with a microphone, add Skype, and, hey presto, you have a mobile phone without that prohibitively expensive AT&T contract. To be sure, this works best if you live and work at a university or some other environment with good wireless connectivity, or if you are prone to hanging out at Starbucks, but the day is going to come pretty soon when wireless connectivity is far more ubiquitous than it is yet now (a lot of communities, including mine, are working on universal coverage). When all this comes together, Skype's gonna rule.