Things like you’re describing were a lot more expensive when you wrote this post (I hope you’re still watching it) but recently I discovered these little gems:
A more detailed data sheet is available from digikey:
They’re basically wireless serial modems. Think of cutting the serial cable between your computer and the robot you are controlling with it, then wiring each end to one of these. The xbee ($19 each) has a 300 foot ideal range, and the xbee-pro ($32 each) has a 1 mile ideal range. Obviously you will need two to communicate. They use CMOS logic, which I think is just normal logic level serial data (please correct me if I’m wrong). I am planning on using two xbee-pro modules as a bridge between a Pololu USB to Serial Adapter and several Pololu serial controllers to make a mobile robot arm I can control from my computer. One pain is that the pins are at a 2 mm spacing, instead of the standard 2.54 mm (0.1 in) spacing. I think they just want you to buy their serial or USB adapters, but many places sell 2mm header receptacles!
Maxstream will try to sell you lots of extra bits and a development kit, which costs a whole lot and you only really need to do advanced programming of the transceivers (frequency and power changes, etc). You can get just the bare units directly from Maxstream, with your choice of a chip antenna, short wire-antenna, or a connector for separate antennas, which they also sell. My lab used a set of the xbee-pro transceivers with wire antennas to make one of our robots wireless. We did get the development kit in case we ever need to run multiple wireless robots at the same time, but the units communicated with each other right out of the box. I’m going to use the panel-mount external antennas, because they are cooler and I imagine they give you greater range.
I don’t know if the pro and the standard modules will communicate with each other out of the box, but that would save a little money if you wanted the longer range, but did not need to get information back from the robot. I will ask about this when I get mine (after I scrape together the money for them) but I think I’m going to get two of the pro modules, in case I want to add feedback sensors to my robot later.