Visiting Los Angeles in July looking for place to stay?

On a whim, decided to book two tickets to L.A. for July 2008. I'm looking for the CHEAPEST, CLOSEST place to stay thats near all the tourist attractions (i.e. Mann's Chinese Theatre, Sidewalk with Stars, Muscle Beach, Beverly hills, Shopping, etc.) I've looked online and all the campsites are pretty much booked and hotels are too far away. any information provided would be greatly appreciated!