My husband and I are expecting our first child, and I'm on the lookout for a diaper bag that could hold my SLR and maybe an extra lens, in addition to the usual baby stuff (diapers, changing pad, change of clothes) and purse stuff (wallet, keys, cellphone). How have other parents solved the challenge of combining both needs, without carrying both a camera bag and a diaper bag?

This question is a bit similar to [this one](https://photo.stackexchange.com/questions/3542/camera-bag-with-extra-space-as-airplane-carry-on), but there are a couple of extra challenges. Preferably, I'd need a strategy to isolate the photo stuff from the potentially messy baby stuff (nothing like spilled milk - or worse - on a 600$ lens...). And of course, I don't need to carry a laptop.

Any ideas? Strategies?