Is there any way to have separate iMessage services for two iPhones linked to the same Apple ID? I share Apple ID with my wife for convenience of buying apps only once and sharing photo and music from one Mac. However, the my iMessages to other people seem to appear on my wife's iPhone. The phone number is used as a Caller ID.
Use separate Apple IDs for iMessage (Settings>Messages>Receive At>tap the Apple ID at the top, sign out, sign in with a different ID). You can still keep the same ID for iCloud (if you want to share contacts, calendars, photostream, etc.) and for store purchases (in Settings>Store).