You can just defer your summons. In LA you just have to show up for one day. If you don't get selected then you don't have to come back and your duty is served. Not sure how other counties handle it though. You can just go and get it over with it or defer it over the phone through an automated system (in most cases). I was out of the country when I received mine last year, called the phone number and deferred it 4 months.