So: the AppleScript menubar item. It's a very handy tool for accessing all those AppleScripts you hear about that automate this or toggle that. As long as you save those scripts in ~/Library/Scripts (where ~ is your Home folder), they'll appear in this AppleScript menu - once you've enabled it. I personally think this menu item should be included in the default set of every Mac, but I'd wager that Apple sees this as a little too nerdy of a feature to drop on brand new users. Fair enough.
To enable this menu (nerd) in Tiger, go to /Applications/Applescript and open the AppleScript Utility. It offers a few options for handling AppleScripts, including turning on this menu and the order in which the menu displays scripts from both the default system level /Library/Scripts (in your main hard drive) and your personal ~/Library/Scripts folder. If you're on 10.3 (Panther), I *think* you have an /Applications/AppleScript folder, but instead of a full-blown AppleScript Utility app, it's an AppleScript called 'Install Menu' or something similar. Back on Tiger in the AppleScript Utility - you don't worry about the GUI Scripting option unless you come across a script that specifically needs it, though I don't think enabling this for simplicity's sake can harm anything either.
If this process went according to plan, you should now have your very own AppleScript menubar item like I have in the screenshot here. clicking it will offer a simple menu of all the scripts you have between the two directories you chose to display. As long as you enabled your personal Home script directory, any scripts you save there should appear in this menu immediately after saving, ready to carry out your bidding.
With that said, why not check out some of our past AppleScript posts, such as one of my personal favorites: an AppleScript from Fraser Speirs that opens iSync, syncs all your devices (such as a phone or PDA), then quits iSync. If you use an application launcher such as Quicksilver, you can tie handy scripts like these to Triggers (system-wide keyboard shortcuts) for even more convenience.