Google Search Results based on IP Address?

I noticed something earlier today.

I was doing a search for a highly competitive keyword in which I knew I ranked number one for (one of my other websites). When one day and over the past couple weeks I found a competitor’s website taking my place. I cleared my cookies and flash objects and did the search again but I had the same outcome. I then called a friend up and asked them to do the search for me… and they had a different result with my site in the number one position.

I thought to myself, “well that’s good, but why on my computer I’m in the second position?”

I did another test with a friend’s computer at my house (on my network) and a competitor’s site was again number one.

I then realized it was an IP issue. I changed my IP address and guess what? My site was back to where it should be.

So even WITHOUT cookies, flash objects and or even logging into your Google account.. you’ll still receive the same Google targeted search results if you’re logged in with the same IP address. Google can track your IP address and server you up stuff they think you want to see.

How long has Google been doing this?