If you're flying to LA, you're probably going to LAX which is near Santa Monica. You'll want to head to the Apple store in Santa Monica -
http://www.apple.com/retail/thirdstreetpromenade/week/20070218.html
Glad you won't be driving. I drove from Houston to LA before which took a little over 2 days. Five days would have been more sane to drive from NY to LA.
I agree with this plan 110%. I have lived in Los Angeles for many years in addition to living in NY for a good amount of time. That being said, there are countless places I have not even visited in LA, and even if I have, I would be more than ecstatic to visit again. So in the case that you have visited LA, I would still NOT recommend leaving.
I don't know your exact flight schedule or money constraints, but assuming you arrive early AM and leave late PM, I would HIGHLY recommend you fallow this itinerary. Come into LAX and make your way to Santa Monica. This is about 15-20 min drive without traffic and about an hour if happen to arrive during rush hour (~ 7:00 AM and 9:00 AM). You will arrive at 3rd Street Promenade where you can stop by the Apple Store and purchase your computer (unless you have it shipped somewhere). At the same time, you have top notch stores that most would be jealous to even step foot in. The 3rd Street Promenade is basically an outdoor mall with great shopping, dining, and even street entertainment. You can find out all you need about the promenade at
http://www.downtownsm.com/ From there, I would make some combination, if not do all, of these choices. Your first choice is to stay in Santa Monica either at the 3rd Street Promenade if you have a lot of shopping to do or by the beach where you can visit both the beach, pier, and Main Street. You can google any of these to find out more information. Your 2nd choice, which I suggest, is to take a 10 minute trip to Venice Beach. There are hundreds of souvenir-style store huts where you can purchase gifts of all kinds for friends and family back home. When I say "all kinds" I mean all kinds. This includes anything from hand blown "water pipes," knockoff sunglasses, and art from local artists. Additionally, while shopping there, you can take in the "California Sun" and truly appreciate what many movies and dreams have been inspired by. The third option, like I said depending on money constraints, is to take a trip to Beverly Hills, also 10 minutes away. This would be my 2nd suggestion in combination with the Promenade. At Rodeo Drive, you can have a field day clothe shopping at the most exclusive stores in the world. A list of stores can be found at
http://honeymoons.about.com/od/allaboutla/f/Rodeo_Drive.htm This is an amazing place for shopping of any kind, yes even window shopping, where you can feel the glitz and glamour of it all even if you cant afford to be a part of it. You will find not only the stores, but the people that make Los Angeles "Los Angeles." Even if not purchasing anything, I would still highly recommend Rodeo Drive for simply sight seeing. Window shopping can make even the fittest of us a bit exhausted. Window shop all you want and then take seat at a restaurant where you can order a coffee, sit outside on a patio facing Rodeo, and simply enjoy the scenery. Lastly, depending on if you actually spend the night or not, and your age of course, Los Angeles is known for its nightlife and celebrity encounters. If you want to have both a great time at a bar/club and have a good chance of seeing a celebrity from the likes of Suge Knight to Christina Aguilera, I would definitely visit one. As for names, just like most clubs, there is an "it" night. So if you want to know what club to visit, tell me what day you are coming in, and hopefully the venue wont disappear as they often do over night.