The standalone installer for the entire program can be downloaded from: http://www.apple.com/quicktime/download
From version 7.2 QuickTime requires Windows XP Service Pack 2 or Vista.
The latest version for Windows 98/ME is QuickTime 6.5.2: http://www.apple.com/support/downloads/quicktime652forwindows.html
For Windows 2000 SP4 it is 7.1.6. http://www.apple.com/support/downloads/quicktime716forwindows.html
This has been successfully tested with K-Meleon 0.7SP1, 0.7.5 and 0.8RC1:
Just run the installation and copy the following files to the K-Meleon plugins folder (if you already have QuickTime, you may find the following files already on your hard disk in the C:\Program FilesQuickTime\ directory or wherever you have installed QT; otherwise, those files will be there after the installation):