Yes. I have approved my 150 for flight with either (but not both) door removed. If I'm taking a strapping lad, I'll take my door off, and thus at least have room on the left side!
I have always felt that Cessna missed a market segment by not building a plane halfway between the 150/152 and the 172. A slightly bigger, faster, fancier two place, which could be stretched to three or four as a 150/152 can. But Cessna knew their market....