It seems to be worth noting that Blogger records stats from ChromeOS users as "Other Unix" running Chrome as browser. Someone with more knowledge about this could probably make something out of this info. My only observation is that ChromeOS doesn't report itself as Linux, but as a Unix platform. I also had a visitor reported as running Linux, but with Safari as the web browser. I assume they must have been running some kind of webkit browser, but it could also be that OS detection isn't that accurate.
http://www.thismachine.info/ states that my OS is an unknown platform
http://www.whatbrowseramiusing.co correctly id's it as Linux! so maybe it is blogger's problem (or maybe there's someone out there running chrome on an other unix?)
I also ran through my 100 mb of free data today. In answer to my earlier question, I was given the option to purchase more with a credit card at this time even though nothing was requested during the initial setup.