MacBook Pro – Fast Alternatives to Crtl + Shift + Eject for Screen Lock

The new MacBook Air and Pro without optical drives lack an Eject key.

I use Ctrl + Shift + Eject a lot to put my display to sleep at the simple press of three keys. Without the Eject key being there anymore I'm wondering if there's an alternative to those very handy shortcuts which required the Eject key.

The alternatives I've found so far are not too good:

• in Alfred type "lock" – too many strokes for fast computer locking
• a hot corner in the bottom left to put the display to sleep – ok, but I get there by error too often and lock the computer for serious productivity bummers
• close the lid of the MacBook Air – puts the Mac to sleep completely and therefore not very useful, when it should keep doing what it's doing.

Is there a similarly fast alternative to Crtl + Shift + Eject for new Macbook?