Bare Bones' TextWrangler is a very useful tool for Web developers, but lacks options for quickly previewing HTML code in your Web browser.
Here is a fun approach for automatically changing Safari's downloads folder to an external drive that uses AppleScript. If you like scripting on a Mac then this may be for you.
Speed Doubler and AppleScript glitch?
AppleScript 1.8.1 confusion
Speed Doubler and AppleScript: a follow-up
AppleScript Keychain unlockers: a security issue
AppleScript for email program selection in Communicator
iTunes and AppleScript: new scripts; new script menu
StuffIt Deluxe crash when AppleScript is not active
AppleScript works-around double-shutdown problem