Is there a last ditch way to revive a frozen OS?

I got my first Mac not too long ago, so I'm still working on getting familiar with it.

The question of the day is, is there something in OS X like ctrl-alt-del in WinXP? A way to kill a rogue process if everything seems to be frozen?

I've had my Mac freeze on me quite a few times already. A lot of times, none of the apps respond, Finder doesn't respond, and pressing the power button doesn't start a graceful shutdown. My only solution has been to hold down the power button and power off.

I've almost never had to power down my WinXP box via the power button. Ctrl-alt-del always brought up the task manager. I would imagine that OS X never really freezes either - I just haven't figured out any way to do anything after the UI freezes. Maybe there's a keyboard shortcut that brings up a terminal? Or a way to switch off the UI and go to just a command line?

Thanks for any tips.

Edit: Last time, I tried option-command-esc but it didn't seem to do anything. I just saw option-command-eject so I guess I'll try that next time.

If an application hasn’t responded for a while to mouse clicks, trackpad scrolling, or other persuasive actions, click on the Apple menu and select Force Quit.
A pop-up window lists all the applications you currently have open. Stalled applications are listed in red and say (not responding) after the application name. Scroll up and down through the list with the arrow keys, or just click on an application name to select — then click Force Quit to exit only that program. You can restart the application from your Dock or Applications menu, but any unsaved changes may be lost.
Simultaneously pressing "Command-Option-Esc" and the Force Quit pop-up should appear. Usually used if your Finder has frozen and you can’t select the pull-down Apple menu.

If neither are working, it may indicate other problems that need addressed.
May want to start with the basics.

Run Disk Utility and see if the HDD needs repaired.
Download OnyX and run the maintenance scripts, delete caches, repair permissions, etc.

Now that I think about it, I think all of the freezes were caused by Flash animations in Firefox. I hear that Flash is pretty buggy on OS X so I assume it's not a problem with my machine.

It would be nice if there was some way to kill Firefox when the entire desktop is frozen except for a spinning beach ball.

[edit]please delete this post. Because I gave an amount of help to the OP. But I only later realised someone else above gave the same info as I did and no need saying the same thing 2 times.