Ctrl-drag the end (or beginning) of a clip on the timeline to stretch it out (slow motion) or compress it (fast motion). A zig-zag line will appear through the event on the timeline to show that its playback speed has been altered.

You can also right-click the event on the timeline, select properties, then specify a playback rate directly, from .25 (4x as fast) to 400 (4x as slow).

By default, associated audio tries to sound normal. If you want audio to sound higher pitched or lower pitched, you have to right-click on the audio, select properties, then change the (something I can't remember) parameter from "None" to "Classic", then tick the box that says "Lock to stretch".

Tim L