Ctrl+Alt+Del has thankfully become less prevalent in the Windows world. It certainly still has its uses though. Back in its hay day, the keyboard command even received a nickname like the ‘three-finger salute’.
Developer of various Mac utilities Two Canoes has created an open source counterpart for Mac OS X with ‘Salute’. It allows you to press Ctrl-Command-Delete in order to receive similar shortcuts.
By pressing Ctrl-Command-Delete after running Salute, you will receive a window that pops up offering quick access to the Terminal, Activity Monitor, or the Screen Saver (to lock the computer). The screen saver can allow you to lock the computer with a keyboard shortcut like the Windows equivalent to Windows key + L.
When you first start Salute or if you hit the Question Mark, you will get a little Help documentation:
Salute allows you to start your screen saver using a keyboard shortcut (ctrl-command-delete) instead of having to use hot corners. If you turn on the option of requiring a password when exiting from the screen saver, this allows you to lock your session with a keyboard shortcut.
You can enable screen saver locking by going to System Preferences -> Security, and selecting “Require password to wake this computer from sleep or screen saver”.
Salute also allows you to launch the Terminal or Activity Monitor. This is handy if the Finder is not responding, can’t be re-launched, and you need to get back into the system for maintenance.
You can also select if you want to go to the Login Window instead of the Screen Saver. This does not log you out, and does not require that you have Fast User Switching turned on.
Under System Preferences -> User Accounts, you can choose the Login Items tab for your account to include Salute to startup automatically when you login. See this guide from Apple for step-by-step instructions: http://www.apple.com/findouthow/mac/#appstartup
I tested Salute out on Mac OS X 10.7 and found it to offer some convenience. It offers pretty nice functionality for a small utility.