In doing a considerable amount of local web development, we often come across the need to modify (or even completely swap out) the hosts file on Mac OS X Leopard.  While it is possible to do this through the terminal, there is a great little tool from Clockwise that works perfectly called Gas Mask.

Features:

• Syntax highlighting
• Simple hosts file switching
• Global hotkeys for file switching
• Automatic flushing of the local DNS cache
• Growl support

Gas Mask is currently at version 0.4 and can be downloaded for free on the Apple Downloads site. Enjoy!