Hope these pictures help... (and let me tell ya, I HATE pix of myself but for the greater DIS good...)
I have a baggallini (sp?) messenger. Got it on clearance @ REI online.
I don't like purses - I have a healthy back bag from L.L. Bean and I hate it. (gasp!) I'm a "money and license in the back pocket" kind of gal. But we knew we'd need something for a water bottle, tickets, car keys, sunscreen, etc. LOVE the messenger bagg! okay....
Here's a shot showing the bag's regular position for the week:
I just realized the bag is almost the same color as my shirt, but you can see it. I'm not a petite person (ahem), but this bag was very comfortable. I've seen other people mention (on other boards) that they found the strap too short, but it's actually very adjustable. There are two slide buckles to adjust, making the strap REALLY long. You could also shorten the straps and wear it over one shoulder like a purse; mine slid off a bit, but I'd do it if we were going in and out (like from car to restaurant, etc).
This picture doesn't show the bag too much, except for one VERY important feature:
Okay... I don't tell just anyone to stare here, but you see that strap going, um, between "the girls" ? THERE is a zipper pocket that hides in the strap. The company says it's for a cell phone, but my cell is a flip phone and didn't fit. However, we kept all our tickets RIGHT THERE the whole week. Believe me when I tell you I had NO WORRIES about someone trying to steal our tickets (I would LIKELY notice

) Also, I didn't worry about the tix falling out of a pocket, or falling out if we took something out of the bag.
Last picture (sorry so long here) - and please DO NOT mention to DH that I'm posting this, but it's proof that a guy MAY wear it:
You can also see the strap against your neck - I actually didn't mind too much - I found my camera strap hurt - but this strap was smooth enough. Although toward the end of the day, I preferred to tuck a shirt collar underneath, as he is NOT demonstrating here.
Hope this helps!