Asghar enquires:

> 
> Is it illegal to sleep in  your car on a public street?
> 

In nearby Berkeley, CA, the "homeless" have bought cheap junker cars, which
they park on the road alongside the "beach", actually it's just a "frontage"
road that runs parallel between the ocean and the interstate. They're 
usually all cleared out by 8:30am.  I came to work early today (7am), and
there were about 25-30 cars (practically the length of the road). 

I wouldn't call what they're doing camping, but they have the cheapest 
oceanfront property in the Bay Area!

I second the opinion about truck stops;  my favorite is in Rapid City,
SD, where my girlfriend (now wife) and I got free showers and towels,
and they let us use the women's shower together!  All of the other
truck stops wanted $10-$15 for a shower, though I could have gotten
a free shower if I could have fit 100 gallons of diesel in my Jetta.

For people traveling in the Western US, some of the Western states 
have awesome rest areas; the ones in Idaho and Wyoming have hot running 
water.  Makes washing one's hair a bit more comfortable.

-Jim