I run piwik, the Open Source web analytics tool on the webschuur server to track some clients' sites and this site.
Piwik released a new, mostly bugfix, version. But one particular new feature, the addon "AnonymizeIP" struck me as very usefull:
Anonymize visitor IP addresses to comply with your local privacy laws/guidelines.
Very little more to be found about this, unfortunately, so I dove into the code.
global.ini.php contains a setting
; number of octets in IP address to mask, in order to anonymize a visitor's IP address; if the AnonymizeIP plugin is deactivated, this value is ignored; for IPv4 addresses, valid values are 0..4"
Setting this to e.g. 3 will mask the addresses, so that you store only the first IP-block is kept. For example, the IP adress from Google (one of the many) 126.96.36.199 will be stored as 74.000.000.000 when set to 3.
I have set this to 2. So I can still guess the approximate region, but can never find out who you are exactly. Great for privacy, yet still somewhat usefull for me.