On: Whose xterm is it anyway?

[arethuza]

What about the real old school approach and try XOFF?

[kps → arethuza]

Or, if you're not stuck on Linux, Control-O (or whatever you've set your terminal DISCARD character to).

[ansible → arethuza]

For those that don't remember... That is ctrl-s. XON is ctrl-q.

[sevensor → ansible]

That's my usual approach. After ctrl-s I usually use job control (ctrl-z) to suspend my misguided cat and kill % to kill it.