I like 'Fred On Something' s KingPing Service a lot (and moved there from a sometimes shaky and out of order pingomatic.com (WordPress) service ). Now Frédérick Giasson (Fred) offers a new service called
which can help you to find out who is linking to your / a specific URL by searching major search engine. Made for Blogger but to use for any URL - checking 'Who talks about it'.
Results are delivered by engines, trends and a trend graph (still in Beta, but works o.k. on my setting) and you can show it on your side to your readers, if you care to do so!
More about how it works and how to use it GOTO Talk Digger
Great Service and very useful! Thank You Fred!