corrideat - 3:30 am on Jul 3, 2009 (gmt 0)

I am (in the first stages of) developing some Analytics system. The original idea is to try it on the sites of my own, even though later it will become publicly available.

It would collect the following data (using ECMAScript):
* Flash version
* Google Gears version
* Screen resolution an color depth
* UA-related information (UA string, version, OS, platform, etc.)
* Plugins installed (Mozilla-based)
* Referrer URI
* Whether the browser is in Quriks or Standard mode
* Local time and timezone information
* Support of ActiveX and XHR.
* Result of some basic DOM tests to check DOM support.

In addition, the use of server logs would provide with:
* IP address
* country of origin
* methods to check whether the user is a new or a recurring visit.

I would like to know what you think about such a system. I'd be glad if you could tell me what kind of information is actually essential to you, or that you would like to be able to know and your current system doesn't provide.

Thanks in advance