QuickTime Alternative will allow you to play QuickTime files (.mov, .qt, .3gp and other extensions) without having to install the official QuickTime Player. It also supports QuickTime content that is embedded in webpages. Works only on Windows 2000/XP/2003/XP64/Vista.
As a bonus, Internet Explorer will play all QuickTime movies that are embedded in a webpage. You do need a media player that is capable of playing QuickTime files. The included Media Player Classic supports it and works very well. The QuickTime Browser plugin supports Internet Explorer, Opera, Netscape and Mozilla. The QuickTime plugins include iPIX and QuickTimeVR.