Deer Park Alphas onwards including Firefox 1.5 Betas; and Flock: You do not need to uninstall a previous version of Flashblock when installing a new version.

Install Flashblock 1.3.4 for Firefox 1.0 to 1.5, Firefox 1.6a trunk builds, SeaMonkey (all builds), Mozilla Suite 1.7.x, Netscape 7 to 8.0.x, and Flock 0.4+. (includes a toolbar button for all supported browsers).

Camino installation: Please follow instructions located at: http://www.macosxhints.com/article.php?story=20041217163514494
(Thanks to John Reinhold for this link.)

K-Meleon installation: K-Meleon 0.9 comes with Flashblock built-in.
For older versions of K-Meleon, please follow instructions located at: http://kmeleon.sourceforge.net/wiki/index.php?id=FlashBlock

To test your flashblock installation, visit this page: http://www.adobe.com/shockwave/welcome/

• If you use Firefox or Mozilla, you must restart twice before Flashblock will work.
• If Flashblock doesn't work, first try deleting or renaming the userContent.css file in the chrome subdirectory of your profile. If you don't know where your profile directory is, click here.