Well the following services provide free backlinks..Many people over here are looking for free backlinks so thought of sharing it
IndexKings.com (minimum 5000 backlinks )
247backlinks.info (1000 backlinks ..I guess)
freebacklinktool.com (500 backilnks, quality )
backlinks.auto-im.com/freepack/free.php (10000 backlinks)
linksoar.com/index.php?ready (don't know about them)
Enjoy !