screenshots in Tiger

I'm a new mac user, but even the thought of "easier screenshots in Tiger":http://arstechnica.com/journals/apple.ars/2005/4/29/142 are appealing. I find there's a wonderful shortcut that dumps a screenshot to the desktop, but in PDF format. Huh? Luckily in Tiger, screenshots are exported as PNGs.

Still, who can remember command + shift + 3? Print Screen is so much more natural (though, I'm sure there's a valid reason, for example if the key doesn't exist on Mac keyboards).