http://www.googleguide.com/advanced_operators.html#link
link: The query link:
URL shows pages that point to that http://www.blackhatworld.com/blackhat-seo/#url. For example, to find pages that point to Google Guide?s home page, enter:
[ http://www.google.com/search?q=link:www.googleguide.com ]
Note: According to http://www.google.com/help/features.html#link, ?you cannot combine a link: search with a regular keyword search.?
Also note that when you combine link: with another advanced operator, Google may not return all the pages that match. The following queries should return lots of results, as you can see if you remove the -site: term in each of these queries.
Find links to the Google home page not on Google?s own site.
[ http://www.google.com/search?q=link:www.google.com+-site:google.com ]
Find links to the UK Owners Direct home page not on its own site.
[ http://www.google.com/search?q=link:www.ownersdirect.co.uk+-site:ownersdirect.co.uk ]
wnersdirect.co.uk