I've recently started using Sipdiscount (www.sipdiscount.com) with a SIP phone (one that plugs directly into a router). Provided you place the phone in a DMZ and set the codecs to G711 or PCMU it works really well. Calls to UK landlines and several other countries are free if you credit your account with 5 Euros or more.
You can also try the system out without registering and make calls of up to a minute. Well worth checking out.
You can also try the system out without registering and make calls of up to a minute. Well worth checking out.
