API to determine whether running on iPhone or iPad [duplicate]

Answer 1

1. Check for the presence of the userInterfaceIdiom property, usings respondsToSelector:. If it doesn't exist, we are on a pre-3.2 device, thus not an iPad.
2. If userInterfaceIdiom exists, use it.

Edit: ... which is obviously exactly what the UI_USER_INTERFACE_IDIOM() macro does, so use that instead. :)