Install both development and iTunes downloaded versions of the same app on one iPhone

I have an app in the App Store. I would like to be able to have the production version of my app on my phone and install debug/test development builds of newer versions of the开发者_如何学运维 app. I am using XCode 4 and it doesn't seem that this is possible. I attempted to change the bundle identifier by adding some numbers at the end and that didn't work. I also added the same numbers to my ${PRODUCT_NAME} but that did not help either. Is there a way to do this? I'd prefer to not generate another App Id in the iOS Provisioning Portal.

I do it in Xcode 3 by setting different bundle name ${BUNDLE_NAME} for a different identifier. plus different name, plus precompile instructions. Works well. Generate the ID, easy. I routinly produce 3 flavors of a build: development, release, and enterprise.

I found a great detailed answer here. The article describes how to automate the process of having different builds for production and development versions of an app, both in Xcode 3 and Xcode 4.