[Twisted-Python] Timing Out Deferreds

I've been trying to figure out an intelligent way of timing out deferreds. I'd like something like this... def myTimeoutMethod(...): ... d = whatnot() d.addCallback(...) d.addErrback(...) d.addTimeout(5, myTimeoutMethod) There are obvious problems with trying to interrupt an existing deferred, but I was hoping there might be just some way of discarding its data when it finally does return, or dereferencing the deferred object itself from the reactor, which might just let it clean itself up on its own. Thoughts? -Ken