What is an application for Mac OS X that let's others view your desktop over the internet?

iChat does screen sharing.

edit :: And it will share audio while displaying your screen. A fast internet connection is needed for it to be smooth.

edit #2 :: And the software you might be thinking of might be Apple Remote Desktop. But that seems like overkill. If both of you are on OS X iChat should do the trick.

LogMeIn is a good, free, and cross platform remote desktop tool. I’ve used it to troubleshoot my friend’s mac from my PC, and teach him how to use logic pro.

Leopard iChat’s Screen Sharing is great.

If you’re both on Leopard, you can use iChat. Setup AIM accounts and you’re good to go.

I have Mac OS X 10.5.6, but my friend has the previous version, 10.4.

I do need something that’s like a webcam solution, like iChat. I’d like to be able to talk to my friend and let her see what I’m doing.

Have them upgrade to leopard then use iChat

teamviewer.com

In Leo, you can go to “System Preferences” and select the “Sharing” icon. In those prefs, you will see “Sharing”. Click the box to enable it and create a strong password. It is basically a built in VNC server. This also is what MobileMe uses to share screens with the computers you have MobileMe set up on. But, like I said it is fundamentally a VNC server and can be used as such. If you are behind a router, you will have setup beyond this to get it all to work. This is another question in itself.

Another piece of good VNC software is called “VineVNC”. This is what I use at home. Also, a good VNC viewer for OS X is JollyFastVNC. Hope this helps.

PS. This is not the most easiest solution, but it is the most “universal”. Meaning you would be able to access your computer from any computer running any operationg system that is connected to the net. Rather than counting on iChat or other OS specific programs. If you don’t need this functionality, that iChat or the web based “LogmeIn” software would be easiest. It may not be free, but it would be easy.