I moved away from Firefox to Chromium (the open source part of Google Chrome). When I moved I search for all the extensions I used in Firefox. One of them was Flashblock. There is also a Flashblock for Google Chrome but I wanted to block all plugins until I say so.
Luckily, Google Chrome has that option. Just got to about:flags and enable on the Click to Play flag (this is available in the latest beta of Google Chrome 9, I don't know about the stable Google Chrome 8). Restart the Browser so the flag comes into use. Then enable click to play for the plugins as follows: Open the Preferences, go to "Under the Hood", Right under the "Privacy" click the button "Content Settings...". Then select "Plug-ins" and choose the brand new "Click to play" option.
When you open pages with plugins an icon will appear in the address bar indicating that plugins were blocked. You can use the icon and enable all the plugins for the page, but I prefer the Click to Play: Google Chrome will put a gray area with a large puzzle peace icon on it. When you hover the mouse on it the mouse changes and an indication appears saying "Click to run this plug-in" with the name of the plug-in under it. If you want just click it. You can also you the icon on the address bar to always allow plugins on certain domains (like Youtube).