you can use quicktime pro to either speed up or slow down your clips, by any amount you desire.
the qt player audio-video controls merely allow you to change the clip speed as it is playing, up to plus or minus 3x. here is how to convert a clip, permanently to a new speed:
1) open file A (the clip you want to change). 2) find/create a clip (file B) which is the length that you want file A to become. 3) select all of file A. copy file A 4) go to file B, select all. 5) in file B pull-down menu choose EDIT - ADD TO SELECTION AND SCALE - enter. this will cause file A to be inserted onto B and play in the timeline of file B. 6) open properties window, delete the original file B track or tracks. 7) EXPORT file, with a new name, in your desired format. be sure to check the export settings box for frame rate. i use 30 fps for speeded-up clips, and 30 or 60 fps for slowed-down clips. on speeded-up clips, if you forget that step, and leave it set for current, you will get an extremely high rate, making the movie unplayable. if you forget on a slowed down clip, you will get a very slow rate, which is herky-jerky. this is because quicktime adds all the frames from file A to file B, setting the frame rate to fit the timeline of file B.
NOTE: if there is an audio track in file A, it will be modified along with the video track. eg slower or faster
NOTE: for STEP 2, creating file B, i use iphoto; select a photo or series of photos, export to movie, scaled and set to desired length. this gives you a custom movie container, any length, into which you can apply file A.
