The O'Reilly Network has posted coverage of the keynotes and congregations of O'Reilly's Mac OS X conference (full coverage, including weblog coverage, is also available).
From reading the article, I found out about a couple of cool new tips and tricks in Panther. The first is a new trick that the incredible Cocoa text handing system offers: hitting option-escape brings up a word completion list (very quickly too - much faster than the auto-complete option in XCode). On top of the other benefits of Cocoa text fields and boxes (automatic spell checking, basic emacs bindings, etc), this is a cool little feature to have.
The other thing is a small enhancement to the "Force Quit" system. Command-option-escape (wow - I didn't realize the similarity of those chords until now) brings up a window listing running applications and a button to force errant (or non-errant) applications to quit. This has been in Mac OS X for a long time and is a much more formal version of its Mac OS Classic equivalent which used the same combination. The enhancement is - if you add "shift" to that chord, the system will force-quit the front most application. Since most of the time, it's the front application that's causing problems, this is a nice touch. You can also see this in action by visiting the Apple Menu, which has the force-quit option, and hitting the shift key. The menu option then becomes "Force Quit NetNewsWire" (or whatever application is in front).
That last feature is a nice long-running feature of the Mac OS menu system, wherein the menus change according to any key modifiers that may affect them. This is often a good way of learning extra keyboard shortcuts. It also keeps the menus clean, while offering options for power users. For example, to restart the computer, selecting the unmodified version of the 'restart...' option on the Apple Menu yields a dialog box asking if you're sure (while also giving a countdown of two minutes, in which you can cancel or continue). Holding option down makes the ellipses go away (remember, ellipses in menus typically means that a dialog box will come up), allowing for a quick restart without the extra confirmation step. It's an extra little shortcut that has to be explicitly enabled (using the option-key modifier), but is nice to have for people more comfortable with the machine. It's also nice that the system communicates this change by updating the menu to show that there will be no dialog box, which leads one to expect that the action will happen immediately. It's a subtle but nice touch.