I am building my first project. It's going to be a simple tank that can be given a set of instructions to follow, forward, backwards, etc. I also wanted to be able to control it manually. I've written the code with 2 analog inputs connected to 2 variable resistors powered by a 5V source that control each set of track. I wanted to make it have some sort of wireless control. I'm not sure which way is better to go. I was thinking of maybe ripping apart a cheap r/c car? Or maybe go a bit fancier and try XBee? But that would require 2 boards? I have the money to spend on XBee, but it doesn't mean I want to go all out. Maybe FM transmitter? I have a while until my motors and tracks arrive. But I am currently deployed so everything takes twice as long to get out here. 
I am trying to get ahead of myself. Thanks in advance.
Just thinking about the same thing... Though I will probably buy xbee would be nice to have a cheap alternative.
I don't need to build a large sensor network, but just to put one sensor one floor lower without needing to put cables all over the place...
I have been looking at these small RF link modules. I guess they will do the trick: RF Link 4800bps Receiver - 315MHz - WRL-08947 - SparkFun Electronics
There are different baud rates and frequencies available, and for only about $5 it is worth playing around with.
/Noe
Hm, i would like to extend the question a bit.. When browsing through RF modules one sees always the 'open space' values - i guess they do not apply to submerse area.. yet i would like to know if somoene here has an idea if there is some rule-of-thumb for estimating the value for underwater applications? I read somewhere that this is impossible because water has different impact on the signal strength depending on the RF frequency, yet i am totally unfamilliar with that whole field... Though i guess that is somewhat right since, for example, underwtaer com systems for divers work in the kHz area instead of the so loved GHz area used for many air applications...
this looks cool, but do you have any idea where to get it in EU? It's kinda expensive to order from US...
The XBee is extremely simple to use. Unfortunately that simplicity is expensive.
For a simple application you may be able to get by with only an XBee. The Xbee
has a uC (8051 I believe). It can be setup to monitor and control digital lines
and to monitor analog lines.
I make an Arduino compatible board with an XBee -- see Loading...
I have some simple software examples at my site.
(* jcl *)
To Odisej
Electrokit.se http://www.electrokit.se/ in Sweden have some RF modules.
I bought my Arduino there, ok prices and swift delivery. Excelent service (they event sent a christmas greeting on mail!)
/NOE