Using Esper to manage real-time data.
I'm flying back from a wonderful event: Strata.
I gave a talk there called "Esperwhispering" that seemed to pique many people's interest. This is the stuff you do when a database just doesn't have the horsepower to answer your questions fast enough.
Esper is an excellent, open-source CEP tool. It's a shame its GPL, but hey... you can't win 'em all.
This presentation gives some insight into what it does and why one would use it. The live presentation, of course, had more information and live demos, but... you had to show up for that (or watch the live stream of the event).