Communication good stuff
First I am going to talk about VOIP telephony. I have been using a Grandstream 100 phone for a few months as an extra phone line. The telephone plugs directly into Ethernet and allows you to plug in anywhere there is an outside accessible internet connection and make calls as if you were at home. I am planning to take this phone to Israel but have tested it in Portland quite a bit. At home I am running a wireless link which allows fast data transfer but lots of packet loss and long ping times. SIP telephones use UDP packets which have no loss correction, this leads to some voice quality issues on lossy connections. The PersonalTelco Project is running a test server which runs Asterisk on a Linux machine. This server acts as a telephone switch and connects to Free World Dialup http://www.fwd.pulver.com/ and Vonage www.vonage.com as well as a local line in Portland Or. Anywhere this phone connects to the internet it will access this server and make the phone active with a Portland number. I wish the GS100 had the ability to store several profiles because I also have a freeworld dialup account and there are times when I would like to dial out from this connection.
FRS Radios
Several years ago the US FCC opened up the FRS radio band in the US it is around 450mhz, a good band for line of sight and local communications. Range is advertised around 1 mile which seems to be accurate even in dense urban areas. Much longer ranges are possible if line of sight is available. In 1999 a climber was hurt on Mt. Hood here in Oregon, by using a standard FRS radio he made a 60 mile radio contact to some boys playing with their radios (they asked their dad to speak to the hurt man on the mountain and he was rescued)
Check the local laws in the nation you visit to see if FRS is recognized as an unlicensed band, it is a great way to save cellular $ but can also land you a stiff fine.  ¶ 8:53 AM