Apple recently released version 2.1 of Apple Remote Desktop, adding a slew of new and improved features (see "Passing the Remote to Apple Remote Desktop 2.0" in TidBITS-746). You can now control and observe remote computers in full-screen mode, and you can also now control and observe both screens of computers that have multiple monitors attached. In such situations, both screens appear in a single window, which may require that you turn off the Fit Screen in Window option and scroll around to access the full extended Desktop. In control mode, Remote Desktop now passes scroll wheel and right-click events to the remote Mac, reducing the need to change working habits. Apple also claims improved support for third party VNC viewers and VNC servers, though I haven't tested the various programs I'd had trouble with before.
Other improvements include multiple line output from Send Unix Command; this makes Send Unix Command significantly more useful for managing remote Macs without having to initiate an SSH session (which still isn't something Remote Desktop can help you do). The Install Package command can now detect whether a package needs to restart the destination Mac and will optionally do so after installation. Remote data collection has been improved, and Apple also improved printing of hardware and software reports. Although Apple says that Remote Desktop 2.1 features "improved file copy for networked home directories," it's unfortunately no easier to copy files to or from remote machines in normal usage. Minor enhancements include improved client authentication using Active Directory and two additional directory services groups, better column sorting in the Remote Desktop Admin application, saving of settings if the Admin quits unexpectedly, and saving of the ordering of network scanners.
You must upgrade the Remote Desktop client software as well, although that's easily done with the Upgrade Client Software command in the Manage menu; the Remote Desktop Admin application upgrades the client software on its Mac on launch. However, the Remote Desktop Admin application complained about the fact that my Remote Desktop client software (which was turned off at the time) wasn't up-to-date on the first launch (I had to force quit the admin application), and for two tries after that, wouldn't launch if the Remote Desktop client was turned off. To avoid this and other weirdnesses, I recommend enabling the Remote Desktop client software before installing.
Apple Remote Desktop 2.1 is a free update; it's an 18.5 MB download via Software Update, or you can download the admin application (16.4 MB) and the client (7.1 MB) separately. Both parts require Mac OS X 10.2.8 or later.