Louise Southerden wrote a great article about travelling light, published in the Canberra Times on 18 May 2013. Her blog is at noimpactgirl.blogspot.com
One of her tips is 'Be present with people. Consider whether you really need to take another photo (and if you do, ask permission first)...'
I enjoy sketching when I'm travelling because often people are interested in what I'm doing and just come and watch, or talk to me. And sometimes they want to have a go.