I wrote this entry on an iPhone with the WordPress web interface, but with a little difficulty. When I tapped in the text entry area for the body of the entry, the iPhone keyboard wouldn’t pop up. The phone didn’t recognize it as a text field. This was probably due to the way the field does visual text formatting. So, I had to switch to code mode, which presents the field as plain text. After that, there was no problem.
By the way, I’m having no problems typing on the virtual keyboard. As Apple said, the key is to trust the intelligence of the keyboard. Just go on typing away, completely ignoring the blatant mistakes you see yourself making, and in pretty much every case each word is fixed up as you hit the space bar. It is quite amazing!