Apple has recently released their Remote Desktop Client 2.1 as a free download. You can install this without buying Apple Remote Desktop 2.1, as the client is bundled free in all copies of Panther. The surprise here is that the client includes a VNC server -- which features support for dual displays! Here's how to proceed:

1. Installing the update, open the Sharing System Preferences panel.
2. On the Services tab, first enable Apple Remote Desktop, and then click the Access Privileges button.
3. On the next screen, activate the VNC area and enter a password.

After setting this up, you can now remotely control your Mac with any free VNC viewer (e.g. Chicken of the VNC), running on Mac OS X or any other OS.

About Chicken of the VNC Software:

Chicken of the VNC is a fast, lightweight VNC client for Mac OS X. A VNC client allows one to display and interact with a remote computer screen. In other words, you can use Chicken of the VNC to interact with a remote computer as though it's right next to you. It's available on the Apple website as a free download. (http://www.apple.com/downloads/macosx/networking_security/chickenofthevnc.html)