We love keyboard shortcuts here at Lifehacker, and Chrome's already got more than a few built in. But if you don't like the defaults, or want to add a few of your own, extension Chrome Keyconfig gives you pretty much endless possibilities.
Chrome Keyconfig comes with a number of keyboard shortcuts pre-configured, but you can easily delete them or replace them with your own if you don't like them. The process of configuring them is very easy; you just type in a key combination in the box at the top, click the add button, and then pick an action to assign to that shortcut. The list of actions is enormous, allowing an amazing amount of customisability in your browsing experience. Furthermore, you can also switch between "normal" and "limited" mode with the escape key (by default), allowing you to have two different sets of shortcuts. This is useful if you have a lot of shortcuts that could interfere with what you're doing (like playing flash games). You can also import and export your shortcuts for use with Chrome installations on your other machines.
There are a few quirks, most notably the complete lack of documentation in any form. Most of the extension is pretty self-explanatory, but there is no explanation of what "limited mode" really is (I had to figure that out myself), nor why you aren't allowed to use the shift key in your shortcuts. There is also a menu of "basic options" which, apart from smooth scrolling, are not even close to descriptive enough to know what they mean. Despite these issues, though, the amount of shortcuts you can configure is more than awesome enough to warrant installation of the extension. We just hope that the developers give us a bit more of an explanation on what some of the options are.
Chrome Keyconfig is a free download, works wherever Chrome does.