I happened across this today as I was going through the Facebook developer forums.
Basically, using the new admin_setAppProperties and admin_getProperties functions, you can create pre-canned FQL queries that are run when you go to a particular page. It still has to run the queries, but it doesn’t have to do the back and forth calls betwen Facebook and your app and have the related delays. You get the results as fb_sig_<name> parameters.
It is explained really well on the Facebook Developer’s Wiki – here.