PSGw (Personal Skype to SIP Gateway) connects Skype and SIP networks. Which means that least *least* cost routing takes one giant step closer to consumer reality. Think the very cheapest calls, all the time, from anywhere. $29.95.
PSGw 2.0 uses SIP protocol version 2.0 and is compatible with most of SIP applications and devices. Note for Asterisk users: PSGw 2.0 is compatible with Asterisk.