Well I have joined the fold on using Skype, I have use many voice programs over the years of being on the net and so far the test I have done on Skype have proved it to be a much better program then the others I have used, I like that the messages and any file are encrypted before leaving you computer , this dosen't mean I would send sensitive data through it it just means no more evesdroppers on the voice chat, the quality of the voice is better than all the ones I have used in the past.
Tranfering a photos I was able to accive 8Kb per sec when we weren't using voice and about 1kb when on voice chat.
The set up is one of the easiest I have come accross, eg:Got my 69yr old mother to dowload and install it with no probs, she was up and running in 10 mins using voice.
Programs I have used: MSN,YaHoo, BuddyPhone, ICQ, AOL, NETtoPhone, EyeBall video and voice, Beta Tester for Telstra's early netphone software.