When I go out for a bike ride or short hike, the Mountainsmith Lumbar Pack is way too big. On the other hand, the Mountainsmith Dart is way too small. So I found this one made by The North Face that's just right.
This Steep Tech Lumbar pack ($59) has a bunch of pockets to keep all your little stuff safe. There's a place for your water bottle and a big pocket next to that for food, a windbreaker, or whatever else you may need. I love the zippered pockets on the hip belt, so you have easy access to tissues, your phone, or an energy bar. If you like to listen to music while working out, the front pocket has a place for your earphone wire. The waist straps are thick and adjustable so you can get a snug and comfy fit around your waist. It comes in black, red, and root green and you can order it from altrec.com.