I too was going to suggest a belly band. Fanny pack would work too, but they're dorky, and basically scream, "GUN!" to anyone else who carries.
Is there a reason a small gun serves you no purpose? I am an advocate of carry the biggest gun you can conceal, but at times, that means a small gun. There are plenty of small guns in good defensive calibers, that are pretty easy to carry. Just a small list:
...and the list goes on and on. All on that list are at least 9mm/.38 SPL, and a few are even bigger, .357 Mag, .40, .45, etc.
As far as what a Bellyband is, just do a Google search for Belly Band Holster. There are a bunch of companies that make them. I don't have one right now, but have used in the past. They work pretty well. Since I plan to start jogging again soon, I think I'm going to pick one up again since it'll be the easiest way to conceal something while running, I think. Massad Ayoob talks about them in several of his books. Their biggest drawback is they are difficult to reholster. But beyond that, they're very concealable, very confortable (relatively speaking, anyway) and usually relatively cheap ($20-$30 range).
EDIT: By the way, what you're asking for is the holy grail of CCW. A full-size gun and holster combo that can be worn with basically any type of clothing, with any type of activity, without printing. If you can figure out a way to do that, you'll be a rich man. If not, *something* has to give.