what sarahvincent said. even though i'm allowed to bring a medical device with me on planes, people handle it very badly. it gets shoved around something fierce in the overhead and there's no room at my feet. i bring small things i can do at night and pack in my checked luggage. fabric to cut and pin, rotary cutters, small cutting board, plastic bags, small scissors, etc.
in la you'll want to walk around at night. there's so much to look at and see. you'll be home before you know it and you can pick up sewing then.
enjoy!