Picasa for Mac

Google:

Picasa for Mac looks and works almost exactly like Picasa on other platforms.

In other words, they ported it using a cross-platform toolkit, and it doesn’t look or work like other Mac applications. Also notable: it doesn’t run on PowerPC-based Macs.

Update: Dan Benjamin:

I’m hoping that a future version of Picasa might be designed for Mac OS X, as opposed to running on Mac OS X. Now that would be a killer app indeed.

KeyRemap4MacBook

Apple’s newer notebooks have a second Option key on the right instead of the more useful Enter key that was present all the way back to the original PowerBooks. KeyRemap4MacBook is a kernel extension for remapping this key (and others) to do what you want (via Ken Case).