Ever wonder what files your Mac is hiding from you? Maybe not, but once in a while there's a need to peek at the stuff OS X keeps you from viewing. Finder does a nice job of hiding the "guts" of some folders, you see, but there are occasions (troubleshooting, setting up a web server, looking for some folders, etc.) when you'll need to view and/or edit these files or folders. Enter hiddenfiles, a simple and unobtrusive widget that'll show those hidden files and folders.
Sure, you can use Onyx or Terminal and do some command line work. But it's much easier to drop into Dashboard, hit "Show" on the blue button and have Finder relaunch, showing all invisible files. I had to click on Finder in the Dock to actually launch it again, but when I did there were those lovely .DS_Store files, staring me down. I use this to remove the hidden _files off my daughter's PC-friendly MP3 player. That way she doesn't have to scroll through resource-fork versions of her songs.
The widget is free and available from developer Matthew Hansen's page.