⇧⌘. shows hidden files in file dialogs. It also works in TotalFinder. Transmit also has an action for toggling hidden files, but it's assigned to ⇧⌘B by default.

There's nothing equivalent to that in Finder though. But you could always assign a shortcut to a script like this:

	set k to "com.apple.finder AppleShowAllFiles"
	set r to do shell script "defaults read " & k
	do shell script "defaults write " & k & " -bool " & (r is 0 as text)
	tell application "Finder"
		quit
		delay 0.2
		launch
		delay 0.2
		activate
	end tell

I use [FastScripts](http://www.red-sweater.com/fastscripts/), but you could also create an Automator service and give it a shortcut in the keyboard preferences:

![](https://i.sstatic.net/Mviay.png)