I think you're on the right track thinking of Christmas hiring. I'm sure there are pleny of retail establishment that would be able to sign you on for weekends only during the season.
Another idea might be to look for work as a caregiver for seniors. Several companies pay pretty good money for people to work as companions and to handle light housework, bill paying, and other tasks seniors may need help with.
I've also heard of people having pretty good luck doing product demos in stores. There's a website
www.snagajob.com that lists lots of leads.