How to copy apps into /Applications

I'm learning-by-doing with InstaDMG and getting along OK until I'm faced with how to install an app that does not have an installer. I mean those apps you would normally just drag in to the /Applications folder. In ARD I just do a copy and all's well. however, InstaDMG seems to want pkgs and only pkgs (even if wrapped in dmgs). Is this correct? If so, is the answer to use Iceberg or equivalent to create an installer? cheers! ---john---