QuickTime 7.6.6 for Leopard is recommended for all QuickTime 7 users and according to Apple brings about "general reliability improvements for iMovie." Additionally, the update addresses a long list of security vulnerabilities related to maliciously crafted audio or movie files that could allow attackers to cause crashes or run arbitrary code. The update is available via Software Update or the Apple Support Downloads page. (Free, 68.63 MB)
Open a Finder Window with the App Switcher
If you don't have any Finder windows open and want to switch to the Finder and open a window in one fell swoop, bring up the app switcher with Command-Tab and tab over to the Finder icon. While still holding down Command, press the Option key, and then release the Command key. You're switched to the Finder, with a new default window open for you.