I have been thinking about this a little and a lot of this is to do with weighting. THe simplest starting point I can imagine is the value of a like in the overall search should be weighted by the total number of likes given by that person.

So a like from Robert Scoble will be 0.0000001% of the value of a like from my maiden aunt who has only liked three restaurants in her home town since she was given a iPhone for Xmas.

What will really force this to take off is the ability for a like from Robert Scoble / Aunty Mable to be tracked to me liking the same restaurant -> and so there being a like-rank value

I think it is this:

  L = ((1/TotalUserLikes) / totalWeightedLikesOfRestaurant) * numberOfSubsequentLikes