If you’d like to use a traditional telephone device to call other phones using Skype Oldskoolphreak has documented the process at http://www.oldskoolphreak.com/tfiles/voip/skypeout_via_ata.txt

It’s not exactly a simple process, and required a virtual PBX installed. The instructions use the Axon Virtual PBX, but note that:

I’m probably sure you can substitute the Axon PBX for Asterisk, seeing as Uplink isn’t hardcoded to use Axon. It’ll require some tweaking though. I didn’t have much luck with it. If anyone wants to give it a go with Asterisk and succeeds, let me know, and I’ll add it to this text file with full credit given.

The process also requires a SIP-to-Skype bridge, so it might be possible to make this work using a SIP Softphone like Gizmo.