You need to register with companies and look to see what they are offering in your area. At this time of the month there will be relatively little left for December as the companies push hard to get all their shops done in the first half of the month so they aren't stuck with unperformed shops during the holidays. Companies that have shops everywhere there is a gas station, fast food joint or post office include Maritz, Market Force and IPSOS.
You can also see who has had shops in your area by registering with the free version of Jobslinger.com and look to see what shops are posted for your area. The chances are good that the shops you see have been taken already by other shoppers but at least it will give you an idea of what companies have clients in your area so are worth signing up with first.