By searching some keywords, I saw that there is a gray timestamp near the title (not URL) of serp, like this:
Blue Title of an result - 5:49pm Description of this page [page-url.com...] 16k Cached - Similar pages - Remove result
What's this?
tedster
2:11 am on Jan 22, 2006 (gmt 0)
It's part of Google Personalized results -- you are logged in, right? I think it records a previous search time when you visited that page.
iProgram
2:40 am on Jan 22, 2006 (gmt 0)
Yes, it's an interesting feature.
sublime1
7:13 pm on Jan 22, 2006 (gmt 0)
You may also see some other interesting features, such as "Remove result", and check out the Search History link next to your account info on the Google home page.