I've got all of my stuff ready for my interview and I am wondering if I should bring along any items to "prove" our marriage is bonafide. I've not read of anyone who is doing DCF being asked to produce photos/documents, but I just want to see what the general consensus is here. Do I need to pack photos, our son's birth cert and others bits 'n bobs for the visa interview?

Well from what i've read nobody else needed to provide that pics/letters etc. I think if they had doubts about your marriage they would have sent an RFE back at the I-130 stage. And if you bring your son with you, you'll already be loaded down with baby supplies. No need to bring things you don't have to provide.

But maybe someone else who has actually had an interview might be able to shed more light

How long have you been married? We'd been married for nearly six years when we began the process and didn't have to supply anything other than our marriage certificate (photocopy with the I-130, original at the interviee).

Two years later this month.

If they haven't asked you for any evidence, don't bring any. They will probably ask you how you met, etc.