Up to now I was using Transcribe! for transcribing solos from records. As it doesn't support video files, I was googleing around and came across the amazing application Finetunes (http://homepage.mac.com/seishu/ssworks/finetunes/finetunes.html
). It handles all the files that QuickTime does, can change speed and pitch, has a filemanager with playlists and works amazingly well! I have no problems on my PowerBook G4 1.33 Ghz, so it works on older hardware, too.
So I am using it now for transcribing from videos and to parctice to my playalongs.