Messenger bag for a man (that doesn't look like a purse)

Pockets. Wear the jacket unzipped or loop it through a belt. You can buy drinks everywhere.

Osprey has pretty durable small slings that stay out of the way.

If he likes and urban industrial look, Chrome has some fun (though not cheap) options.

http://www.chromeindustries.com/us/en/

I've got one of their smaller cross body bags that I sometimes use instead of a purse, and can say that both design and construction quality are very good.

I've also heard good things about Timbuk2

http://www.timbuk2.com/tb2/

I carry an old version of Patagonia's Half Mass messenger bag. Its small enough to pass as the personal item/brief case carry-on item in combination with my RS Classic carry-on that hasn't broken yet.

You can get it in subdued colors. http://www.patagonia.com/us/product/half-mass-messenger-bag?p=48316-0

Henrietta, Eagle Creek makes a variety of small to medium sized "man bags". Check out their web site and then see if you can locate a retail outlet so he can get a hands on look see. TC

The local thrift store (run to benefit a hospital) had about 5 briefcase-style messenger bags when I was there this week -- priced around $10 or less, Some of these were from tour companies or professional symposiums, with logos on the bag, but you can turn the decorated side towards your body if the logo bothers you. Good enough to last through a few weeks of travel, and disposable at the end of the trip.
(I recommend going where the well-off people donate.)

I just picked up the new Eagle Creek Site-Seeing Tablet Courier.

http://www.amazon.com/gp/product/B00F9S95DQ?ie=UTF8&camp=1789&creativeASIN=B00F9S95DQ&linkCode=xm2&tag=ibssupportgroupf

It's small but will hold everything you mention. It only weighs 8 oz. and costs $45. All zippers are lockable and the bag comes with a lifetime warranty.

Check out Bagallini's messenger bag- MES160C Classic . My husband used the khaki colored one, and I used the black one.

A daypack that is not too structured can be carried slung over one shoulder and under the arm, when you feel the need to be more secure, and used normally other times. Heck, with camera in pocket, I would use a plastic shopping bag for the rest.

My husband just bought a Kenneth Cole leather messenger bag. It is surprisingly light, and they are on line for under a hundred, but he and the bag look like dynamite. Leather is what the men in the cities are using.

A couple of years ago I got my husband a Patagonia Daily Grind bag, but, unless there are some lurking on the shelves of some obscure vendor somewhere, they may no longer be available.

Do a Google images search to see what they look like. It's the horizontally oriented one. There are still some vendors who have it listed, complete with full description and specs, but most say that they have none to sell. If you look for it stick to the main 3 words because it can be called a messenger, shoulder, laptop, computer or any other number of labels bag. It can also be called a briefcase.

My husband LOVES it and carries it everywhere he wants his iPad and the rest of his life with him. He wears it crossbody while traveling. However, when we are out and about in Europe, he relies on his pockets and moneybelt.

I mention this bag that you may not be able to buy because its features are so perfect for his needs. Anything with similar features and subdued style would probably work. I know my husband would not want any of the newer, similar but flashier bags Patagonia seems to have available these days.