Question: I have some large resources that I only need for my simulator runs—I'd like to have them automatically excluded from all device builds. Is there any way to do this with Xcode 4 short of custom build scripts that copy the resources?

Answer: 
I went with a Run Script phase with the following:

```
if [ ${PLATFORM_NAME} != "iphonesimulator" ]; then 
    echo "device build -- removing resources..."
    rm "${TARGET_BUILD_DIR}/${UNLOCALIZED_RESOURCES_FOLDER_PATH}/test_a.mp3"
    rm "${TARGET_BUILD_DIR}/${UNLOCALIZED_RESOURCES_FOLDER_PATH}/test_b.mp3"
    # reveal the binary in the Finder
    /usr/bin/open --reveal "${TARGET_BUILD_DIR}/${UNLOCALIZED_RESOURCES_FOLDER_PATH}"
else
    echo "simulator build..."
fi

```
Custom build scripts is your best friend in Xcode. Have the script delete the resource after the build and before the code sign.