The “Facebook Doesn’t Own My Friends” Chrome extension lets you export your friends’ data
From the description on the website:
“Facebook Doesn’t Own My Friends is a Chrome extension to export your Facebook friends’ contact data.
Despite what Facebook says, if someone is your “friend” and you can see his/her email address on his/her Facebook info, they are probably OK with you emailing them.
Facebook doesn’t let you export this data, so they expect you to click on each of your friends’ pages, copy their email address (or other contact information), and paste it into your email client. Kind of ridiculous? Yes.
Facebook Doesn’t Own My Friends will let you export all (or some) of your friends’ contact info, to CSV or directly to your Google Contacts (GMail).”