Apple is no longer restricting Mac OS X betas to paying developers. Anyone with an Apple ID (which is, let’s face it, essentially every Apple user at this point) can now sign up for the OS X Beta Seed Program to test unreleased versions of the operating system. You have to agree to Apple’s OS X Beta Seed and Confidentiality Agreement and install the Beta Access Utility to view betas in the Mac App Store. After WWDC, we’ll see if this applies to major releases of OS X, or just minor updates.follow link
Sleep (and Lock) Your Screen
When you are walking away from your computer, it's fairly common practice to start your screen saver and lock your screen. But did you know that there is a built-in keyboard shortcut in Mac OS X to sleep the screen?
Press Control-Shift-Eject and your monitor sleeps without engaging the screen saver.
Apple Opens Mac OS X Betas to All