Female yuppies have notoriously heavy bags filled with laptops and lipsticks, flip flops and folders, gym clothes and gum, iPads and iPhones, Advil and antibacterial, cash and combs. If you haven't noticed, I love alliterations.
Thankfully backpacks are making a comeback, and not just for back-to-school. Hipsters are jumping on the Herschel bandwagon, and stores are bolstering their inventories with a variety of on-trend offerings. My favorites for this season are pictured above, and they're all suitable for vegetarians!
Aside: Matt & Nat, Freedom of Animals, and Stella McCartney are exclusively vegetarian brands, so you never have to worry about any of their products containing leather. Herschel and Zara offer some vegan bags and others that contain real leather, so check the composition before purchasing if leather-free living is important to you.
Back to why backpacks are the crème de la crème of carryalls - they evenly distribute weight on both shoulders, so you don't end up with uneven trapezius muscles ("traps"). Not only are asymmetrical traps funky looking, they can also cause headaches, back pain, balance problems, and flexibility issues. If you carry large textbooks, a laptop, and/or other heavy items, stick to backpacks with thicker straps. Also, be cognizant of your posture - strike a balance between Quasimodo and a trust fall fail.
I know what you're going to say - backpacks look childish and switching your purse between shoulders should be sufficient. WRONG! Backpacks can look sophisticated and have versatile functionality. Moreover, I used to be a cognizant shoulder-swapper. Despite my best efforts, my right trap was bigger than my left (indicating unconscious uneven usage), so I tossed the tote and bought a backpack.
I'm not saying that you have to wear your backpack to a fancy dinner or girl's night out ("GNO"). Small crossbodies and clutches are great for special events, but backpacks are best for everyday schlepping.
Courtesy/Security Note: Take your backpack off and hold it by the handle when you're on a crowded train or in a cramped elevator.