I am pretty sure I can't change from landscape to portrait mode on the netBook. But let me add this. I can read and buy from any source, Amazon, Sony, B&N, etc. and then use the correct reader software to display the file. I find the B&N, MobiPocket and ThomRaider the best. Amazon's kindle software the worst but it is new and should get better.
Here is a shot from the B&N on my Asus. The herringbone effect is in the camera's capture, not on the screen.
Having the Sony 600, I wanted to buy a new ebook. Sony price about $18.
Amazon hardcover price about $17. Kindle price $9. B&N ebook price also $9.
I will buy from B&N. Best reader software, best price. This is an option I don't have using a Reader.
I will edit to add this. In the photo no flash was used. I was directly in front of the screen. There was a lamp behind the computer. Notice there is no glare. NONE! Perhaps it is me but positioning the ebook reader to achieve no glare is a pain in the neck.