Firefox only (Windows/Mac/Linux): On Monday we showed you how to speed up Firefox by vacuuming your fragmented database regularly using a copy-and-paste Error Console command. Sounds like a pain, right? Vacuum Places Improved handles it for you with a mouse click.
This experimental extension adds a small icon to the Firefox status bar that, when clicked automatically "vacuums" your Places database—the one that slows down Firefox when it gets fragmented. You can also automate the task by ticking the Automatically clean places checkbox in the Vacuum Places Improved extension Preferences and entering your desired number of Firefox startups since last cleaning.
It still doesn't solve one of the biggest items on our Firefox wishlist (i.e., better memory management), but at least its an easy way to execute one of the workarounds.
Vacuum Places Improved is an experimental extension (so install with caution), works wherever Firefox does.
Vacuum Places Improved 0.3 [Firefox Add-ons via gHacks]