AnyMailFinder.com - Find anyone's email address
Dux Soup - Dux-Soup is a lead generation tool for LinkedIn.
Hunter - Find all the email addresses related to a domain
CloudSponge - Companies from every industry use CloudSponge’s Contact Picker to get access to their users’ address books.
EmailMatcher - Find anyone's email address in a matter of seconds, for free
BuzzBuilder - BuzzBuilder is a web-based lead generation tool that manages targeted email marketing campaigns and generates B2B sales leads.