Well this is definitely not everyone's "cup of tea" but Palm Springs is not far from Joshua Tree National Monument. In the summer months, expect daytime temps well over 100 degrees although the nights can get quite cool. Like Death Valley, the humidity is generally quite low.
Years ago I had a camping experience there in February that I'll never forget. The landscape at Joshua Tree is intriguing and very surreal; like something that Salvador Dali might create!
Another experience you might find "different" is the town of Quartzsite, Arizona at the Calif. - Arizona Border. Quartzsite is a flea market / campsite sort of place where vendors travel in trucks and RV's from all over the US with all sorts of odd, exotic, handcrafted items. The only place that you might find a stranger presentation of goods would probably be on Ebay! 
PS - I did a little research and found that the "swap meets" in Quartzsite generally take place in the winter months (January and February). So I would not expect as much going on there in the summer months.
[ Edit: Edited on 10-Jun-2009, at 17:08 by Derestanne ]
