Have Just A Phone Number? iOS 6 Facebook Integration Can Fill In The Blanks
m.techcrunch.com
m.techcrunch.com
There might be a problem of spam whereby one person creates a fake persona with their phone number and pretends to be someone else, but I think facebook could solve that problem.
Found a new, partial name + a number in your phone the morning after? Use the "find friends" feature to find the rest of the details[^1] to get in touch without looking like so much of a fool[^2]. You didn't get everything, without making a friend request, but it was a starting point. Obviously it works both ways - people can find and get in touch with you as well (that may be a pro or con, depending on your outlook) - I probably owe my current relationship to this feature!
[^1]: This doesn't work for everyone, but the hit-rate in the 20's-mid 30 year-old's is pretty high in my experience. [^2]: Not guaranteed!