Google Analytics is a kind of standard for this. Only if you are not among those paranoid about Google's invasion of privacy and sneaking into your details.
i am one of those paranoid about google knowing my location, etc. But i use Google Analytics for website monitoring, and when i dont want google or anyone else to know where i am, i leave my cell at home.
It's more than paranoia actually. Google has been very intrusive these days. Nothing bad for common people like us, I guess.