Apple’s latest iteration of the iPhone will come packed with 512 MB of RAM. This is just another example of how today’s smartphones are turning into powerful and tiny personal computers.

The first two generations of the iPhone only had 128 MB RAM. This was followed by the 3GS, and most recently by the iPad. They both came outfitted with 256 MB of RAM. This appears to be the bare minimum amount of RAM needed to be able to handle multi-tasking, which is reportedly supported by the iPhone OS 4.

This might explain why the resource intensive iMovie App will only run on the new iPhone 4. It will not work on any of Apple’s other mobile devices. Video editing has always been one of the most taxing tasks for any computer, requiring stout processors and loads of RAM. Other competing smartphones usually carry 250 MB and 400 MB of RAM.

Apple refused to declare how much RAM would be in the new iPhone, or at what clock speed the A4 processor would run when it introduced the new smartphone at last week’s WWDC keynote. Rumors that are circulating suggest that the processor might be underclocked compared to its iPad counterpart in order to obtain greater battery life.

The iPhone 4 is set to launch on June 24, 2010.