Can someone tell me what this cactus is?

[Lev_Arris]

The owner was kind enough to give me a clipping of this nice cactus. There are so many different cactus I don't know how you all do it.
My guess Pachycereus weberi?



Here is one of the clippings

[m4rkz0r]

It looks like a cereus sp. you can tell by the skinny ribs. Notoriously hard to identify and most would probably name it cereus peruvianus which is a generic name for cereus species of unknown origins. There's two good articles in the cacti articles section on the subject.