I've been recording all my screen casts with SnapzPro and then re-recording them with Camtasia Studio on Windows to be able to edit them. This is to say the least, extremely tedious.

Yesterday I stumbled into ScreenFlow, an all-in one screen recording and video editing application with very cool features like call outs, video actions, key press display, etc. You can even capture audio from multiple sources and record your iSight at the same time as doing your screen cast. Afterwards you can combine them by manipulating the individual tracks and for example get a cool narrator call out that sits in a corner of the screen cast.

I also like their approach towards the recording operation itself. You don't have to constraint yourself by deciding which area of the screen has to be recorded beforehand. With ScreenFlow you just record everything and crop it in the editor afterwards. They are using a custom algorithm that only records changes that appeared on the screen, so even my 2560x1600 resolution was recorded together with audio and the iSight video, without any sign of a hick-up. I love it!

It might be a tad on the expensive side ($99), but considering the functionality that you get, I don't think it's exaggerated.