I am currently an undergrad at UC Irvine, and I must say, I will miss it! If you like physical activities definitely get aquainted with the ARC (the recreation center). They offer a variety of classes from surfing, to sailing, to rock wall climbing. Irvine itself is a quiet community, so if you want to do ANYTHING past 9pm you actually have to leave it to find fun. I recommend Newport Beach, Downtown Fullerton, San Diego, or LA for the nightlife. Laguna Beach and Corona Del Mar are great places to spend a sunny afternoon. Whatever you are into, you'll probably find it nearby. You need a car though, because public transportation is almost non- existant.