Usually there's an Angel Tree at Blue Baker, one in the mall, one at HEB, and then also at several area churches.
For another idea if you have time around lunch time, you can deliver for Meals On Wheels. They can always use more people to deliver and the people you deliver to love to see the kids if you take them with you. We did this for several years at Christmas and now that my son is old enough to drive, we do a regular route every other week.