[DylanDmitri]

I would love a restaurant review site that could tell you “your brother’s friend from college has been here once and liked it”.

[__MatrixMan__]

I'd definitely use that, though I'd prefer a social graph protocol which restaurant pages just sort of tap into, rather than having a dedicated site. That way we can use the same trust graph for many applications rather than having the restaurant review graph be separate from the scientific peer review graph which is separate from the trusted mechanic review graph etc...