eEye Digital Security is offering its Retina Scanner as a free download from its Web site. It’s available for both Windows and the Pocket PC. Registration is required, and you’ll get a follow-up call from an eEye rep, but hey, free is free.

(Free as in beer for those who make the distinction.)

We went ahead and downloaded the package at the ISP I work for and fired it up. It’s about what we expected, and from our office we picked up the same number of wireless networks as NetStumbler. However, it displayed a lot more information on the main screen and it offers a few additional options.

For starters, it offers brute-force WEP cracking. Which means you’ll only use it on your own network, right? Right? Good lads.

Another option is to detect unauthorized devices. You simply load a list of known/authorized MAC addresses on your newtwork, and Retina Scanner will show you what doesn’t belong.

Finally, there’s a reporting option that spits out a nice, printable document containing a summary of everything Retina Scanner found. It’s got the eEye logo stamped all over it, but that’s not a big deal unless you were hoping to hand the report to a client.

Like NetStumbler, Retina Scanner didn’t display as many networks as Kismet running on Linux, but I suspect that’s a Windows (and/or driver) limitation as we observed the same thing on a different hardware combination.

In all, a good tool for your wireless kit and quick-and-dirty audits.