Whether he is bringing coal to warm the hearth or taking away naughty children to feed the demons, he needs a strong and sturdy sack to hold his load. The same applies to the busy photographer who might have to carry a number of lenses in addition to the basic body. Thus the vast industry of bag manufacture and supply.
Every photographer should have one. Most photographers have more than one - I have 7 and I have met someone with 13. We avoid each other's eyes when we pass in the street but we KNOW...
Well, if you would like to short circuit some of the shame and just get one to do all tasks - camera. lunch, stolen goods, etc. may we suggest the Lowepro Passport Sling II bag. Goes over the shoulder and has 7 definable and changeable storage areas that can mould themselves to the body shape while still not attracting the attention of the pickpockets.
They come in black or army green and can cope with a shower of rain outside or a damp jumper inside while protecting the expensive photo devices. We highly recommend them and sell quite a few.