Although being able to screen share using the finder, another method of screen sharing with Leopard is through the use of iChat. Today I performed some software optimisation and trouble shooting for a colleague who is working in the United States. What I was able to do, was to share his screen from Australia and by using iChat, perform the tasks at hand.
This will however only work if both computers are running Leopard.
Now not only can iChat be used to communicate with friends and family all over the world... but now you can be called up to fix their computers... just what you wanted!!!
While I am on the topic of ichat, something else I would like to point out is the new feature "iChat theatre". This new feature allows you to share such things as iPhoto albums and documents through iChat. This is a great if you wish to "show" someone either photos or documents without having to upload them. Your holiday slideshow can now play to family across the globe without having to upload/ download the raw files.