Here's something surprisingly useful.
Rollyo lets you create "search rolls" ie. short lists of sites that you may want to search. In theory, it didn't sound that exciting.
But then I made Synaesmedia search, a roll which searches all my writing : on ThoughtStorms, Blahsploitation, the SdiDesk wiki and Optimaes. Instantly several fragmented domains are unified. If I know I've written something but can't remember where I wrote it, or want to find everything I've said about, say, currencies, then it's now easy.
Given how I've allowed what I say to become fragmented between various venues, this is really useful.