My Ubuntu 10.04 desktop went to 100% proc and load avg of 20, none of my 10.04 servers or Debian stable servers were affected.
This fixed it:
date; sudo date `date +"%m%d%H%M%C%y.%S"`; date;
You are a lifesaver. All morning my desktop's load has been pegged at 20. I upgraded FF, Chrome, etc. and no impact. I was dreading a full re-start, as I have lots of windows, tabs, etc. open. The above command knocked the load down to almost nothing in seconds.