Nice video recording software, free...

Hi everyone.
I'd like to ask about any free video recording software available on the internet... Nice software i mean, that it would be able to record a part of the screen, and wouldn't lag my actions, what i am doing.
If it's not possible, then at lag the screen after the recording finished, but not lag it, while the recording is in progress...

Thanks.

I personally dont have any suggestions outside of looking in the similar threads section at the bottom of this thread.

Free BUMP until someone can give an answer.

camstudio is perfect for what you need
i use it for game videos but you can use it for anything
you can zoom in on things.
heres a youtube video of how to use it (the video is taken with came studio )

Thanks for answers... I think, that something's bugged in my code, when it's being played on lower FPS... It misses some frames or something... Anyway, thanks for answers.