The only viable alternative to PageRank I know of is social search: show me results that my friends (and friends of friends and so on) liked/bookmarked.

Delicious sort of tried it but never executed well on the search side.

In a way it's a personalized PageRank algo with users linking to pages they like and to other users they follow. This always made more sense to me than a global authority ranking.

When looking for a babysitter you want recommendations from friends you trust, not some global ranking of popular babysitters.