For those who dont know, www.lostcousins.com is a free site when you put in census details of anyone you are related to (not just ancestors) from the 1861, 1881 and/or 1911 census british census (and others like USA). If any other members have put in the same person then it notifies you and you can then buy a subscription to the site (which I dont think is very expensive although I havent done it), and then make contact with the person through the site so it is still confidential until you want to give them your personal info. Every 6 months or so they let people make contact with matches for free and I have just waited for those in the past.
From the site:
"LostCousins is the ONLY family history website able to match you with cousins researching the same ancestors
AUTOMATICALLY, ACCURATELY & CONFIDENTIALLY
Simply enter the relatives on your family tree who were recorded on selected US, Canadian, British, or Irish Censuses - then click the Search button!
Our automated matching is close to 100% accurate, so nobody else needs to see your information - and when you do find a 'lost cousin', you can be certain you're related!"
Im not trying to sell it!

I personally have found 3 lost cousins who I am in regular email contact with. We have been able to share so much amazing information because in one case our mutual ancestors were brothers with 6 other siblings and we both had information on 2 or 3 different siblings.
Amy from Oz