I am really new to the who Arduino community. I've been working on making a wireless method of launching model rockets which has lead me to a lot of research for different wireless radios. I thought I would put all of what I found from the different radios onto a single form so other people, like me, can come and use this as a reference.
I did a lot of researching the different wireless technologies for my launcher. At first I turned to WiFi. I thought it would be super awesome to be able to create a little web page I could access from my smartphone and just use an html form to send a signal to the Arduino. I tried this out with one of my colleagues WiFly modules, but it was so complicated I gave up after a week of having nothing more than a nice terminal connection over the wifi.
My next thought was XBee because of it's support in the Arduino community and it's extremely long range. But I soon found Nordic which drew my attention away from XBee. However, there was not too much documentation on the Nordic modules as there was on XBee, or even WiFly for that matter.
I also thought I would take a look at Bluetooth because it is so widly supported by nearly any phone, laptop, tablet and netbook on the market. I was instantly draw to Bluetooth because it was something that I was similar with, I use Bluetooth to play music, and even use my PS3. I thought it would be easy, fun and cheep to set up a Bluetooth module with my Arduino so I purchased a $10 Bluetooth module from China. When I plugged the module in it flat out didn't work. Status lights came on but I could not for the life of me figure out how to work it. I posted many questions on StackExchange, but no one could help me. I was still facinated by Bluetooth however because of the extreme range of support for the devices. I decided to bite my losses and dish out the $65 for a high end, 100m transceiver from SparkFun.com. The high end transceiver that I purchased is amazing. It supports SMA Antennas and I have never dropped a byte.
Here's an overview of the different types of wireless communication; I have put a '**' by the feature of the particular feature that I think really sets each one of these radios apart from the others.
1) Bluetooth - Cost: $65/module -** Comparable with nearly all modern day technology. - Uses SPP (Serial Port Protocol) - 100m range (High end transmitters) - 115200baud rate (115.2Kbit/s) - http://www.sparkfun.com/products/158
2) XBee - Cost: $55/module - Large support community - Easy to link 2 XBee cards together -** 10km range! (Again, the high end models) - 156kbit/s - http://www.sparkfun.com/products/9099
3) Nordic - Cost: $20/moduel - 100m range - Max 2Mbit/s (Only 250kbit/s at 100m) - http://www.sparkfun.com/products/705
4) WiFi - Cost $90/module -** Can be used on a network! -** Up to 54Mbit/s - 40m range - http://www.sparkfun.com/products/9954
I hope this helps you find the right module to make your project wireless!