Hunter - Find all the email addresses related to a domain
Foursquare - Foursquare is all about helping you find new ways to explore your city.
AnyMailFinder.com - Find anyone's email address
Tripadvisor - The Tripadvisor mobile app is available for the Android and iOS platforms. It can be used to create reviews of hotels, restaurants, and to chat with other travelers on Tripadvisor forums.
AeroLeads - AeroLeads is a lead generation software which finds prospects with email and phone number.
Yellow Pages - YP.com local search connects you with over 19 million local businesses.