Using Skype to make international calls (using your existing phone)

For the past few months, I have been using AU-600 to place and receive international calls through Skype. It is a USB device about the size of a deck of cards. The USB cable, of course, plugs into your PC running the Skype. Apart from that, it has two telephone (RJ11) jacks. The first one takes the telephone cable coming from the wall, and the second one goes out to your telephone.
With this setup, whenever somebody calls you on Skype, the installed software hijacks the call, and rings your phone instead. You can also initiate Skype calls from your phone using some prefixes (default is ##).
Other useful features include call forwarding (for example, to your cellphone), conference call, among others. I have been using it for around 3 months, and have been very happy with it. I have installed it on both ends (caller and callee). It frees you up from the PC (as long as you have a cordless phone, but who doesn't).
The only factor for some people might be that you have to have your PC on all the time. This was not a problem for me, as one of them is on all the time anyway.