So what is FastScripts? It's an application that sits unobtrusively in your menu bar, and gives you easy access to scripts via its menu bar icon, or a global keyboard shortcut. I tend to use it via its shortcuts.
Why should you use it? Well, how about I tell you why I use it? Basically, I use FastScripts as a replacement for Apple's Spaces, since I think Spaces sucks.
So, instead of having multiple spaces with Xcode in one space, or irc + iChat in another, and WebKit in its own; I create multiple scripts which hide all applications, and then brings forward just the ones I want. For instance, here is the script I've got set to control-keypad 2, which lists my "social" apps:
tell application "Colloquy" to activate -- this delay lets me take my fingers off the hotkey delay 0.2 -- hide all apps, from within Colloquy tell application "System Events" to keystroke "h" using command down & option down -- let the apps hide delay 0.1 tell application "System Events" to set visible of process "iChat" to true tell application "System Events" to set visible of process "Colloquy" to true -- There's probably a better way to do all this, but I haven't found it yet.
Here's how to show the Finder, and hide all other apps (which I have set to control-keypad 7).
tell application "Finder" activate set visible of every process whose name is not "Finder" to false end tell
And I've got scripts that do similar things for just VoodooPad or Acorn, and one for Xcode + Terminal, and one that kills VoodooPad and brings up Xcode, and since you can have applications defined by shortcuts as well in FastScripts, I've set some up for specific applications like Twitterrific, Mail, Xcode, etc.
I think this is a better way to manage multiple workspaces. The best part is nothing unexpected ever happens! If I click on WebKit in the dock, all my windows stay in one spot and WebKit just comes up. With Apple's Spaces, I wasn't ever sure what was going to happen.
Anyway, check out FastScripts, it's pretty rad. And I'll see if I can get Daniel to support JSTalk sometime soon as well.