Realtime Screencaputer – $99
Records desktop activity, video, audio, sweet editing tools like fade background, zoom foreground window, and nice support
Not free – but cheap – $60 for full version
Realime capture, pause/resume, follow mouse, record mic audio, record system audio, webcam support, upload to web, records keystrokes, and more. Demo showed moving it to iMovie for adding text and additional graphics.