Arthur and Associates plants themselves at various local malls to do seasonal photos such as photos with Santa. We take the kids (3 and 6 this year) to Redmond Town Center to have their photos taken with the Big Guy. We try to go early in the season, right when they first open so that we don't have to wait in line for too long (if at all). You can either pick up your photo at the mall a few days later or have it mailed to you. They accept credit cards.
They were patient with my daughter (3) who wasn't sure whether or not she wanted to be around this Santa person. She finally caved and they managed to get a good photo... of her. They partially cut my son's ear off in the photo. My husband said maybe we can get a retake but I don't want to go to the mall and do the whole thing over again.
The cute thing was that in addition to a candy cane, they handed out a rubber duckie decked out in a Santa outfit.
They have a website: