Do you mean at design-time or runtime?
At design-time, copy and paste (on the toolbar or use Ctrl-C/Ctrl-V or right click and copy or paste) should work fine for single or many objects at once. Remember that when you paste in the new layout you'll see the + mouse pointer and need to click to place the pasted object(s).
If you are talking about at runtime, you can't copy from one layout to another, but you can create an instance of the object using System-> Create Object so long as an instance of the object appears on at least one of your layouts, however you are creating a default version of the object, not pasting a copy from another layout. I don't usually use it, but you can experiment with the global setting for an object if you want to maintain its state across layouts.