I'm not sure what all the gripes about keyboard navigation are about. I know a lot of people have already commented on the issue, but I have found that OS X keyboard support is the best out there. ALL menu items can be assigned a shortcut, global or per application (just remember to quit and relaunch the application), menu And menubar items can be accessed via keyboard (along with the dock, window buttons, and drawers), the anachronistic Caps lock key can be remapped to another Meta key (Ctrl for unix types), and the option key does all sorts of wonderful things (try option + backspace when editing text, or try bringing up the keyboard viewer and holding down option). OS X also generally supports entering the first few letters of a word to navigate (e.g. try going to a Finder folder with more than one file that starts with the same letter and type the first few letters of the file that you want to choose).

Of course, the really serious keyboard junkies are using Quicksilver, which has been likened to a command line interface for modern GUIs. It takes some work to learn it and to configure it to your liking, but QS is simply the most amazing way to interface with an OS that I have ever experienced. And speaking of command lines, OS X's default shell is bash, which is the de facto shell of GNU OSes everywhere. It's a good way to start learning about how OSes really work.

As far as the issue with entering information in drop-down menus in Safari, use a gecko-based browser like Camino or Firefox (Camino is more OS X integrated). In Camino for instance, I can type in "il" in the state pull down menu on a web site to select Illinois instead of Iowa or Indiana.

So what is my gripe then? That stupid "enter" button on Mac laptops next to the right command key! I use Doublecommand to salvage it as a very useful second option key, but I just don't know why it's there or why it ever existed in the first place. The only difference I can tell is in iTunes where "enter" will rename a song, but "return" will play it. I think it's there to match the faux number pad with num lock on, but c'mon, enter and return are the same button in every other application! If it doesn't turn into a second option key in future laptops, I hope there will be an option in Leopard to remap the enter key into another modifier key, like Tiger offers for caps locks.