Here’s a tip for developing Firefox Extensions in FF3.
My personal favorite feature is the “Extension Builder” — it that lets you install a development copy of the extension . That is, you can run an extension from your working copy/dev folder. Without EDE, you’d have to — uninstall an extension, restart Firefox, install, restart — every time you wanted to test a change. With it, you can just restart Firefox one time, and your dev extension is reloaded. When doing heavy development, I have personally saved over an hour per day from this one feature.
The sad part is that this feature does not work in FF3. The option is just grayed out. But, there’s a workaround. Load up FF2 with the same profile that you use for FF3. Use EDE to install the extension from disk like you normally would. Then, quit FF2, and launch FF3. Since the extension is tied to your profile, FF3 will load your extension from your dev folder, just like in FF2.