I hold my Kindle Touch & Sony T1 in my left hand & easily turn pages. My thumb goes out over & toward the middle as I tap the kindle touch, and my hands are on the small side (all you have to do is tap toward the middle of the page). Same with the Sony. I swipe at an angle to the left with my thumb. My sister is left handed & has had no difficulty with the Kindle Touch or the Sony 350.
I do not tap or swipe with my fingers. That is awkward for me.