I'm no expert on touch screen, but from what I can read from this site (http://www.touchscreens.com/intro-faq.html) Right-clicking can be done with additional software

>I'm so glad some of you're having fun with this. But this was a question asked by one of my client, even though I specifically said to get a mouse.
>
>Anyway, so, from all the giggling, I take it that there is no way to right click w/o a mouse... on any type of screen.