We’ve been big fans of Skype for a long time since back in the have a found it an absolute must have since living in Lanzarote, for both work and keeping in touch with family and friends.
Skype to Skype calls and video calls are free, as is the messaging, but what we like most about it is the cheap phone calls. At the time of writing this we currently pay é0.17 to call landlines in the UK and US on pay-as-you-go.
Also, just recently Skype has introduced a flat monthly rate of €3.95 for unlimited calls to landlines within Europe which seems like a damned good deal to us!
If you don’t already have a Skype installed you can download the free software.