Ad hoc or infrastructure? I have been using a WiFi shield with my arduino board.... I had to download software in order to set up the shield to connect to my network (wep)..... What I am trying to say is that there is going to be more to it than just buying WiFi hardware and plugging it in...

A lot more!

There are discussions on here about changing the BT module for a WiFi module (not a USB one though). Some of us gave up with the idea due to some of the issues that arose... i.e. not enough current to power the WiFi module, virtual com ports being needed for it to work correctly, problems with the modules settings etc.

I don't think any of us who tried were ultimately happy with the results. I gave up the day the v4 was announced.

Alan

Ditto here: Set up was a real pain and then throughput was poor as well.

Sparkfun.com uart wifi module or http://www.sureelectronics.net/

Edited.

sureselectronics.com doesn't exist...

As Alan said, once the V4 was announced the desire to mess around with a WiFi module which came complete with a whole host of problems just went.

I am sure I'm missing some here but amongst the problems with the WiFi modules available were; The 3.3v on the Bluetooth module connections does not provide enough current to run the WiFi module therefore requiring an additional regulator just to get the module to power on correctly. The use of a virtual com port for the module to be usable, this means installing additional software and while there are free virtual com port solutions the ones which worked best you need to pay for. The throughput of the modules is very poor, this gave poor speed and in most cases a lot of lag between sending commands and the EZ-B responding to them. Very little documentation, most of it is in Chinese. Confusing software for module configuration, no instructions come with it and labels within the software are not clear. Difficult configuration, many people wound up with the modules being locked in modes which meant they could not connect to them with the configuration utility and a hard reset was required. No actual instructions anywhere on the process required to hard reset the modules back to factory settings. High price tag. It's more than likely going to be cheaper to buy an EZ-B V4 rather than the module and regulator.

Honestly, I would recommend getting a V4 if bluetooth or USB is not good enough.