Best account to open for a friend's child?

A group of us would like to open a savings account for the 1-year old child of a friend of ours. We don't necessarily want to open a 529 because there's no guarantee he'll want to go to college.

A high-yield savings account sounds fine, but is there another type of account where a handful of us could easily contribute over the years and it would have the best interest rate and tax benefits?

We're not necessarily concerned with his parents randomly using the money, though it would be nice to know it would have to be used for his benefit...that seems rather abstract, though!