[Foomandoonian]

Same here. In addition, I usually attempt to perform an action that will result in a visible response, like scrolling or selecting text, so that if/when the app does start responding again, I'll see.

I also sometimes move the window or switch to another window to see if it's the app or a bigger problem.

[whattheken]

I usually switch to another window or program as well, in the hopes that the other window/program will distract me long enough to give the slow app an opportunity to recover. If other windows/programs are slow as well, then I start killing processes.