Finally! A decent Skype client for the iPhone. I've just downloaded it today (yes, it's free) and it seems to work great. The cool thing is that it support multiple protocols so under same interface I now have MSN too. It can also do Google Talk, ICQ, Twitter, etc. It seems (haven't investigated, only tried it quickly) that they've disabled Skype calls over 3G (for obvious political reasons), but I'm more interested in the Chat features.
Nearly forgot: www.fring.com