Due to Bell Canada's evil ways, Skype-In doesn't allow Canadian phone numbers, so I rent one through DIDWW. It rings through to a VM I have set up running Asterisk (the open source PBX / VoIP server). Our laptops (and my new HTC Legend) have softphone clients installed that pick up the calls coming through Asterisk. I also pay Skype for unlimited North American calling (3$ a month), but when my wife and others in the house want to call folks in North America, they have to login to my Skype account, which is not exactly ideal. This has worked OK for us for a couple of years now, but I recently came across a way to connect Skype as an outgoing gateway to the Asterisk server. The process is fairly well documented via these three sources:
In my case, I was running Asterisk inside a VMWare ESXi virtual machine, so I had the added complication of no real audio devices. Skype won't route your calls unless it thinks it has an audio device, so if SipToSis seems to be doing it's thing but Skype never connects you, this may be your problem. Thanks to a helpful tipster though, the problem is easily solved through the use of the Linux dummy sound card driver (like a virtual sound card for the operation system). Just edit the skype-start script provided by Ward's instructions, and add this line ahead of the other commands:
modprobe snd-dummy enable=1
Now my family can use our soft-phones to dial out using my Skype account in the background. It's especially useful for me on my lovely HTC Legend (have I told you how great it is?) as Skype does not yet have a universal app for Android.