Anecdotally, something like 30% of my friends list (not particularly tech-savvy skewed) probably share their phone numbers. It's also one of the most useful fe

Anecdotally, something like 30% of my friends list (not particularly tech-savvy skewed) probably share their phone numbers. It's also one of the most useful features of the whole site, if I'm out somewhere and realise I suddenly need to call someone whose number I can grab from Facebook.