1. Aerobics/Fitness. You can do aerobics or other gym-related fitness activities in running shoes, cross-trainers, or any sneaker that provides support and cushioning. Some manufacturers have shoes specifically designed for aerobics (for example, the Reebok Freestyle), but you don't need us to tell you that you can do aerobics in something called an "aerobics shoe." If you're just going to the gym to lift weights and saunter around trying to look cool, you can wear canvas shoes, hiking shoes, or just about anything else, but no sandals (stubbing your bare toe is extremely painful).

2. Baseball. You don't have to have 'em, but molded cleats are ideal for baseball. You can also wear running shoes or cross-trainers, but whatever you get, make sure they provide good traction.

3. Basketball. Basketball requires basketball shoes. Not only do you have to wear basketball shoes and no other sort, but you must also replace them no less frequently than every six months, lest you get arrested by the basketball fashion police.

4. Casual Wear. This isn't really an activity, but it's probably the most common use for sneakers anyway. Just being casual is one of our favorite pastimes. Just about any of the shoes we describe can be worn around as casual footwear, but we recommend walking shoes or canvas shoes, running shoes or basketball shoes, and cross-trainers or tennis shoes, in that order (from most to least recommended).

5. Football. Football requires molded cleats, and you'd be ill-advised to try to play with any shoe with less traction than these provide.

6. Hiking. Hiking "boots" have evolved from their heavy, awkward origins to look more and more like sneakers. Hiking shoes are the best choice for hiking, because they provide good ankle support and traction without being too heavy. Running shoes and cross-trainers are okay, too, but they're not ideal because they won't protect your ankles from scratchy underbrush or joint-jarring slips on uneven terrain.

7. Running. We hope nobody is surprised that we recommend running shoes for running. Most other shoes are too heavy and/or don't provide enough cushioning, thus wreaking havoc on your knees and ankles.

8. Soccer. Soccer is best played in molded cleats, but plenty of people adapt running shoes or cross-trainers for soccer as well.

9. Tennis. Again, it should come as no surprise that tennis shoes are best for tennis. Many people play tennis in running shoes, canvas shoes, or cross trainers, but these shoes are not ideal because they don't provide adequate support for the side to side movements required in tennis and other racquet sports.

10. Walking. Walking is a pretty low-key activity, so pretty much any shoe with good cushioning for the soles of your feet would be sufficient. There are, however, walking shoes that are designed for the particular comfort of the walker, and we recommend them for those who walk for exercise or transportation.

SoYouWanna know more? Check out our full-length article SYW buy a good pair of sneakers?