I should make one clarification point: Running lots of apps for no gain to you will be using the battery... but it will be using the battery due to CPU processing, accessing sensors, data via 3G and wifi, etc. It won't be using power because of RAM.
So yes, uninstall apps that run background processes that you no longer want. But not because of RAM, but because of everything else the app could be doing.
I should make one clarification point: Running lots of apps for no gain to you will be using the battery... but it will be using the battery due to CPU processing, accessing sensors, data via 3G and wifi, etc. It won't be using power because of RAM.
So yes, uninstall apps that run background processes that you no longer want. But not because of RAM, but because of everything else the app could be doing.