Restaurant.com (creators of the Entertainment book) have a great special going on today (10/1) only. Use coupon code “ WOW ” to get 90% off regular rates. That means $25 gift certificates go for $1 and $10 certificates go for $0.40
There are over 800 venues on Restaurant.com in the LA area and if you “buy as gift” then you don’t need to select which ones you want to use right now. The "gift certificates" never expire but be sure to look at the restrictions, as most have min purchase requirements. Stock up when its cheap but only get them if you know and like the restaurants participating.