Images for lenticular prints can be masked  and combined using Photoshop you need to know the lpi of your lenticular film tho. The book "Photoshop 7 Magic" has a Tutorial on how it's done and her's a link with alot of info and believe they still offer SuperFlip if you get your lenticular film from them www.microlens.com/

Yahoo has a Lenticular Group also tho I haven't checked it out in ages , you should also google this subject as there is quite a bit of info out there.