I find some of the Lifehacker content a bit hit and miss, however occasionally they post something which makes it worth keeping on my RSS list.
The Keyboard shortcuts roundup post is one of those. Granted it's all stuff you could probably find elsewhere with some googling, but here, someones done it for you. The Windows ones are pretty weak, if you don't know most of these then you probably have a piece of fruit showing somewhere on your computer, but the Firefox list is pretty nice (especially nice as I was googling to try and find the way to give focus to the location bar the other week).
Hey, they're missing a list of shortcuts for Lotus Notes in there.. uhm.. yeah..