If you use a diaper bag, use a small one.  You don't need to pack enough supplies for a weekend trip for one morning at the mallor a visit to the doctor's office!  Here is a simple list of suggestions:

1. Two or three diapers
2. Small baggie of wipes
3. Disposable changing table cloths
4. Bottle and formula
5. Extra nursing pads (if needed)
6. Burping cloth
7. Hand sanitizer gel
8. One small toy or rattle
9. For longer outings you may also want to add a spare set of clothing with a small bag to put dirty clothes into

Remember...the more you bring, the more you have to carry!