You can walk with your wireless phone chatting with Skype friends for free, you can make free call to your mom if she is connected to the Internet. You can make your telephone network with servises, voicemail, etc and chat there using your old phone. Skype wireless phones are expensive, VoIP adapters cost ~$60, but you can make it for free if your have details.. from old TV, Radio or other electronics.

Link: Simple Skype VoIP analog adapter