QuickTime Player in OS X Lion has the capability to merge multiple video clips into one movie. Simply drag the clips you want to add into a movie window. QuickTime Player will automatically scales or crops the clips so they match the dimensions of the movie. You can even trim the head or tail of any clips before saving the combined clips as new movie. If your video editing is just trimming and combining clips, instead of the more elaborate iMovie, you can just use QuickTime Player to achieve the same result.
A lot of training materials these days are delivered via video. These screencast and demo videos are great learning tools, but some video might be of slower pace than what you can absorb.
A great way to solve this problem is to speed up the video playback. A 45 minutes training video can now be completed in 35 minutes or less, saving you precious time.
For QuickTime X in Snow Leopard (Mac OS X 10.6), the way to speed up the video playback is to click on the Fast Forward button. Click once, the playback speed changes to 2x; click again for 4x and then 8x.
The doubling of speed (2x, 4x, 8x) is not suitable for video learning. To select a finer grain of speed increase, hold the Option key while clicking on the Fast Forward button. The first click will adjust the playback speed to 1.1x; click again for 1.2x and so on until 8x. Hold the Option key and click on the Play button to revert to normal speed.
Depending on the video training materials, you might find that you will have no problem follow all the audio and video for speed ranges around 1.2x to 1.5x.