We have 4 hours to kill, anything close to the airport worth seeing, or a decent restaurant in or around the airport???

Is the layover for an international flight? If so, you'll want to be back at the airport 2 hours prior to flight. Which may not leave much time to really get out and enjoy yourself. There is an upscale restaurant there at LAX at one of the former control towers. It's got a great view, but pricy. Unfortunately I can't remember the current name. Just keep in mind that you may not want to lug around your carry-on bags and such. And lockers aren't always readily available.

Santa Monica isn't far away but you would have to arrange transportation. otherwise - the restaurant in the center of the airport is supposed to be pretty good

Here's the review from Zagat on the restaurant described at LAX:

Encounter

LAX
209 World Way (bet. Terminals 2 & 6) LA, CA, 90045-5807 (310) 215-5151

"Meet George Jetson" at this "space-age" Cal-Continental in the middle of LAX, a "cool place to hang while waiting for your flight"; while the setting is indisputably "chic" and "dramatic", the food gets mixed reviews: some say it's "not bad for an airport", but the less generous call it "a close encounter of the awful kind."

Search on Zagat.com under Los Angeles and then by neighborhood. They have an entire section just for LAX. You could take a taxi to any of the nearby restaurants. Daily Grill is a good choice.

If I were you, I wouldn't take a chance missing your connection flight. LA is a huge place and everything is spread out. With the LA freeway being always congested, I wouldn't venture out and possibly missing the connecting flight.
I had and 8 hour layover at LAX on my way back from Australia to NYC and all I did was check myself into a hotel room and got some "zzzzz".

if you can sort out baggage, boarding passes, etc. and feel comfortable about the time,you might go to Venice Beach, which is not that far north of the hotel, walk along the sand for a while, watch the muscle builders, buy some souvenirs, and maybe catch a bite to eat.
BAK

Don't risk it. With LA traffic, 4 hours isn't really enough time to get somewhere, enjoy yourself and get back to your plane in time. Just enjoy one of the restaurants there at the airport and take a walk around the airport to stretch your legs between flights.

I would be interested in hearing what you did during your layover. We have a 6-7 hour stop and would like some suggestions too!