Perhaps "Pop"? Still fun, still alliterative, and it keeps some relevance to "pin". It might be more of a stretch to tie the name to the product, of course, bu

Perhaps "Pop"? Still fun, still alliterative, and it keeps some relevance to "pin". It might be more of a stretch to tie the name to the product, of course, but if you said (of a photo) that you'd "pop it on pinterest" in a few places it might catch.