Eh, I don't know if they'll be able to do that too effectively because of NAT and whatnot, but they can certainly use this information in their PageRank calculation. Knowing what pages people visit is an even bigger vote of confidence for the site than seeing how many pages link to it.
Yes. I meant if you're not behind a NAT they can correlate your IP with your gmail cookie when you do a search and thereby link a record of the sites you are visiting to your profile to serve you more targeted ads. Apologies for the ambiguity.
