tool used to create screencasts

I was just wondering which particular tool you used to create your
Ruby on Rails screencasts

snapz pro + imovie


Snapz Pro X + Quicktime Pro + Camtasia

@Adam: I used IShowU + IMovieHD… looked terrible cos it tried to do everything in HD and the screen caps were regular square pixels. I switched to using QuicktimePro instead… but could you maybe PM me and elaborate more on how you do it?