DingoTel has an interesting product called DingoTel 2Way ( http://www.dingotel.com/2way/index.asp ). This a hardware and software solution that allows to connect almost any regular 2way radio to a computer and then take its pair and walk anywhere in its range (usually 5 – 10 miles) and make free calls over the Internet.
The software recognition module installed on the base computer allows controlling the VoIP software using vocal commands sent via the mobile radio. You can start and end a phone call using only your voice.
It’s a nice idea but for the moment I don’t see any practical applications. Anyway if you want to experiment there is good news: the product has a very good price tag and you can purchase it from different retailers. DingoTel service looks as well very promising.