Currently Being ModeratedMay 1, 2013 3:25 AM (in response to Allison_Accounts)
There is no way to merge Apple IDs.
Content from multiple Apple IDs can be on a computer and iDevices. Simply authorize the computer for the additional Apple ID and put the content on the computer. Then the content can be synced to the iDevice.
The other option is to stop using one of the Apple IDs.