Time elapsed or remaining!
This is Leopard only. This is a very cool tip that I found out on the Macworld.com video podcast. What it does is it lets you toggle between the time elapsed and the time remaining for a video in QuickLook. It is so simple that I don't really know why I didn't figure it out before this. To switch, you simply have to click on the time elapsed. You can click again on the time remaining to switch back. Thanks to Macworld.com for the tip.