Here's a quicky on larp groups in Southern California


www.onlineeffects.net -- Live Effects. Houses 3-4 different larp groups running the gambit from high fantasy to post-apocalyptic zombie combat.
Location: Plays almost every month in Malibu Creek, CA (near 10,000 oaks)
Cost: Varies 75-100+ tends to include food and access to hot showers

www.xaria.org - Campaign. While infrequent and by invitaiton only, this is one of the more elaborate immersive LARP groups in SoCal. Contact someone about an invite if interested (I'm one of those someones) Cost - free, provide own food
Location: Varies

www.dyingkingdoms.com - High Fantasy feel, plays nearly every month. Extensive profession/crafting Cost - minimal, provide own food
Location: Varies

And, as always, check out LARPSpace.com for other LARPers in the community

Have a friend who was interested in trying out Dying Kingdoms