While doing exploratory testing it would be nice to be able to record the screen (in a non-intrusive way), so if a defect is found the steps to reproduce it can be easily reviewed.
Are there any good screen capture tools (video) out there that will not slow down the testing machine?
I have tried a few different applications (I don't remember what they were, as it was a while ago), though they all seem to slow the PC down to the point where they are unusable for this situation. Would I be better off recording the feed to the monitor using external hardware, or is there software out there that can do this?
EDIT:
I run tests on many different Windows OS's, so the tool has to work equally well on XP as it does on Win7.
One of the issues I have noticed with most screen capture software, is that they just seem to be taking screen shots every second or so. This method causes the mouse to flicker, and slows the PC down too much.