- What browser and version you are using
- Your operating system
- Your screen colors and screen resolution (oooh, that seems important)
- Where you are in the world, your IP address, and your connection speed
- When you visited, how long you stayed and on what pages
- Where you came from to get here
I do not share my Google Analytics data with Google. I opted out of that part. I will not use your data for "marketing purposes" but just to make sure the web site is meeting the needs of people who visit. I do not collect any personal information whatsoever.
If you don't want me to collect Google Analytics data about your visit, don't let me. If you use Firefox, you can use the Noscript add-on. Noscript is great, I use it myself. With Noscript you decide who gets your data and who doesn't. If you use a different browser, look around for a "script blocker" for it. (Or try Firefox, it's the best ;)