I checked my site for my main keyword and it was ranked #9 (it is usually between 61 and 75). I went to page 2 and then back to one and it was gone. It was back at 65. Does that mean anything? I thought it was weird because I didn't do another search - i pushed the page link in the pagination. It's never been that high even though the site's a year old and in the top 10 on all other engines.
Google's pretty much going through a bout of randomness at the moment what with all that BigDaddy business going on. You'll probably notice a fair few people noticing the same effects.
It's not really "randomness". The different results are caused by hitting different datacenters. Normally, when they are all in synch, you wouldn't see this but then there are one or more centers out of synch with the rest you will see this sort of fluctuation. When you send a search query, it is automatically directed to a datacenter which is closest to you and/or experiencing a lower load at that instant than other centers. A few seconds or minutes later, you may be retrieving the same results from an entirely different datacenter.