We have registered for this Columbia diaper-bag
at Babies R Us, because it looked big enough to hold the bulkier cloth-diapering essentials, change of clothes, etc. AND was "sporty" enough that DH wouldn't feel weird carrying it.
I am still looking to find a smaller, daypack-style bag that would do for short outings . . . but since we do a lot of camping in the summertime, and have out-of-town family that we will be visiting for weekend trips, I figured a large bag would be a good option for us.
I thought about just using one of our regular backpacks (I still have the Eddie Bauer one that took me through University many years ago), but the bag isn't waterproofed like a diaper bag, and I would be worrying about leaks all the time because of carrying around dirty cloth dipes. I think for our daypack bag I may just order a wetsack and use it to line a small backpack.
I'm not a huge fan of some of the options on the Columbia bag (like the small pocket, specially marked with a pacifier so you won't forget what is in there!
, but it seems like the best that was available when we were looking.