I just installed Skype on my PC to have a look at it, but really wonder what it adds. I am already available through ICQ, MSN, AIM, Yahoo and IRC, and most of these services also support audio chats with reasonable quality. In my opinion Skype is just another IM client. I don’t want to have yet another client, I only want that the existing clients work together. Of course, I don’t have five applications running, I use Trillian, but it does open five network connections over different ports.
For the moment, you can Skype me at icg-jeroen. If I find it useful, I will keep on using it.
Brain tags 
The only advantage I can see that Skype has, is that if you ahve a headset with a microphon e and someone else has it too, you can call cheap over the Internet. If not, they relay your call for a low sum per minute (0,02 ? per minute to the US – from the Netherlands) to a regular line. But as Jeroen already said, Trillian contains all messenger services in one GUI, why use yet another one? Go for Trillian!
Well, the test lasted exactly one day. I still haven’t found the additional value over an MSN or Yahoo audio chat, so I removed Skype from my PC again.