mountain lion for my computer?

I have a Apple iMac "Core 2 Duo" 2.66 20-Inch (Early 2008)
- MB324LL/A -

currently running Leopard. can I install mountain lion on it, and if so, do I need to go through all the updates, snow leopard, etc? thanks.

Mountain Lion isn't available anymore. However, Mavericks is available for free and is supported by your iMac.

Since you are running Leopard right now, and Mavericks is only available through the Mac App Store, you have to upgrade to at least Snow Leopard and then update to 10.6.8 to get the MAS to be able to download Mavericks..

You can purchase Snow Leopard by calling Apple and paying $20..

i have snow leopard, just never installed it. I could do that, and then I could install mountain lion directly? I can get mountain lion on line, I'm sure. thanks for any help.

If you have Snow Leopard, go ahead and upgrade and then run the Software Update to get updated to the latest version and the MAS will show up. You can then download Mavericks..

Be aware though that starting with Snow Leopard support for PowerPC based appellations was dropped. So you might want to check the system requirements of your apps and upgrade them to ensure they will work with the newest version of OS X.

As far as I know...Lion and Mountain Lion are still available (I bought Lion a couple of weeks ago): Hopefully they won't disappear anytime soon:

OS X Lion (10.7) - Apple Store (U.S.)
OS X Mountain Lion - Apple Store (U.S.)

- Nick