I will say that for casual crawls I have went ahead and started using SWK's "Nightstalker" sporran which has room for a camera, phone, flask, keys, pocket knife, wallet, and a few other essentials. Being a dad I'm likely to bring a stack of bandaids and neosporin as well.

Yeah, it's a very, very casual sporran, but my shoes (Blackout Vans off the wall Hi-Tops) aren't exactly classic gear either, and when I say "casual" I'm talking t-shirt + kilt at the park or on a crawl.