Dock needs Hide Application command

[Lepton]

There should be a Hide/Show Application command in the dock menu that pops up when you press on an application's icon.

[Jay]

I agree, but if you cmd-tab to an app in the dock, you can press cmd-tab and hide it (holding down cmd the whole time).

[griffman]

I think Jay left out "...and hide it by pressing H (holding...)"

Also, you can option-click from one app to another and it will hide the app you're switching out of...

-rob.