Keyboard shortcuts are the kind of thing that you either love or hate. Some people simply cannot get used to them, but I sincerely recommend you to give them a chance: you’ll move faster inside applications, perform tasks more easily and notice a remarkable improvement in your productivity.
This optimization can be applied not only to desktop applications but also to web services, which are so popular nowadays. In fact, the people at Mashable have managed to gather a collection of more than 200 keyboard shortcuts that you can use in many different web services such as Netvibes, Wikipedia, Blogger and most of Google apps.
I consider myself a heavy keyboard shortcut user but still, I have something to complain about: why do shortcuts change from one application to another? Why don’t they create a standard? Opening a new file can be Ctrl+U or Ctrl+N, but the latter can also mean “bold text” in other applications… or wasn’t that Crtl+B?