Computerworld came out with this excellent article showing 7 ways to keep your identity from being completely profiled by search service providers. Google for example can easily keep track of your search footprints and identity because they can easily cross-check your search queries (your IP addresses are apparently logged) with your log-in information, say for Gmail.

Here are the 7 tips (but believe me, it takes real patience and skill to do these):

1. Don’t log into search engines or their tools – A really hard thing to do. But the easiest way is not to do a search while logged in to one of their services. And I have been doing that all along. What you can do is open up two browsers – one for Google services (say, Mozilla) and one searches (IE). You might also want to keep several profiles with Firefox.
2. Block cookies from Google – Google keeps track of your search sessions via cookies. But clearing your cookies can cause other helpful cookies website log-in information to be cleared too. Good thing Firefox lets you block cookies from a specified source. Tools->Options->Privacy tab->Exceptions then enter www.google.com. See? If you don’t want Google to track you with those porn searches, better use Firefox.
3. “Refresh” your IP address – This is easily done when you’re hooked up to residential services. All you have to do is to turn your modem off, leave it off a while and turn it back on. As for my case, this works. I’m still in the same IP range, though, but at least a different address. Now offices usually have static IPs so you’d be better off using anonymizers like Tor.
4. Use a different search engine – Ixquick is a search engine that claims to delete all information about your searches within two days. Unlike google which keeps track of everything, when the government legally forces them to present data, kaboom! You’re dead. If tehy do so with Ixquick, there’s nothing to get.
5. Don’t include personal information in your searches – Egomaniacs (like myself!) have probably Googled themselves once in a while. But in the process, we’re just helping them build profiles about us. Tsk. Swallowed by one’s own hubris.
6. Do your sensitive searches in a public hotspot/terminal – Particularly hotspots that don’t require log-ins. Just be careful though when logging into these public hotspots, crackers might just be on the prowl to get you too!
7. Avoid using your ISP’s search engine – If your search engine provider has its own search engine, then don’t use it. Remember, you might have divulged a lot of information to give them when you applied for their service. This makes it easy for them to just keep on building your profile from there.

Jeez. This all makes us all paranoid, doesn’t it? It’s too X-Files for comfort, boiling down to one simple tip – “Trust no one.” Scary.

For the more detailed tips, better read the whole bit from Computerworld.