I found this article on messenger bags... pretty interesting.

Messenger bags shoulder the load for hip teenagers

By Charles Passy

Wall Street Journal

Most parents probably wouldn’t wish a career of delivering packages by bicycle on their kids. But urban messengers are exerting a strong influence on back-to-school fashions – at least when it comes to book bags.

As over-the-shoulder messenger bags replace backpacks in school hallways, retailers are expanding their selections. Online store eBags offers about 800 messenger styles, factoring in all of the color choices; that’s an eight-fold increase since 2001. The site is about to expand its selection with a “build-your-own” line that allows buyers to customize straps, flaps and other features.

They might be cool, but are they functional? We purchased five models online and recruited three high-school students to test them out. Style ranked high on their list of priorities, but so did capacity – so the students stuffed the bags with books and binders to gauge volume. Then the panelists carried the loaded bags, which are generally worn across the body, to judge their comfort. (Messenger bags have been criticized for not being as ergonomic as backpacks because they put all of the weight on one shoulder – but try telling that to a teenager. Some experts advise rotating the bag from shoulder to shoulder periodically to ease the burden.)

The Timbuk2 Classic Messenger Bag, for $80, was so cartoonishly big and unwieldy the panelists rejected it almost outright. “It’s humongous!” said 14-year-old Molly. They were also bothered by the none-too-attractive large strips of Velcro for attaching the main flap, the lack of a pad on the shoulder strap and the glaring lack of exterior side pockets for storing such modern-day essentials as cell phones and MP3 players. One parental thought: The sheer size of the bag, in a nylon fabric, guaranteed it could hold a decent amount of study materials.

The $130 Diesel Canvas Messenger, from Urban Outfitters, had the opposite problem. The judges called the design very hip – it’s described in the catalog as “futuristic military” – but it wasn’t very practical. It couldn’t fit much more than three textbooks, three spiral notebooks and a small binder, which is barely a full load for school these days. And 14-year-old Jacob called the strap uncomfortably “bulky.”

With the $65 Manhattan Portage Europa Deluxe Bag from Luggage.com, everyone liked the bag’s durability (it’s made of a rugged fabric called Cordura) and expandability (you unzip the bottom to increase volume). But it lacked a pad on the shoulder strap, and the teens weren’t too excited about its utilitarian look. “It reminds me I have to go to school,” Molly said.

The eBags Thunder bag, made from nylon, didn’t win many points for styling, either. “Kind of blah,” said 15-year-old Maresa. But it was comfortable to carry and highly practical, with numerous compartments and side pockets, including ones tailor-made for a water bottle and an MP3 player. It also eschewed the usual Velcro or clips in favor of a magnetic closure for the front flap, which our panelists called “neat.” Its capacity fell in the middle range, fitting about four notebooks, three textbooks and one binder, with room for many other items in its smaller compartments. And its low price tag, a parent-pleasing $40, was a real draw. It’s Best Value.

For Best Overall, the Kipling Madhouse Expandable Bag, for $60 from WorldTraveler, took the prize. Everyone found it sturdy and easy to carry, with plenty of storage – when fully expanded, it managed to fit 10 spiral notebooks, three textbooks and two binders. It had an adjustable, padded shoulder strap, plus a hidden compartment inside for personal items. The bag, in a crinkly nylon fabric, looked up-to-date and playful, and the panelists took special note of the attached key chain, featuring a thumb-sucking primate. “Love the monkey,” Molly said.