It is very possible to use a touch screen to naviate around sl, however it is a bit combersome.
I use my iphone (works on ipad better) to remote my desktop machine ... all the heavy grapihc lifting is done by the desktop and the iphone just handled the remote session. Works well over what was 3g (even though they call it 4g now)
For the remote session I used a app called splashtop which even sends the sound from the desktop to my phone (but no sound going back from phone to desktop) this allows me to see a seen and move about. I actually float the arrow keys up from splashtop so its a bit easier to use but agian you just double click to navigate where you want you AV to go and it walks there.
However to be honest that eats through battery fairly quickly and so 9 times out of 10 I am just logging in to have a quick chat with people and in that case will go with the text based solution called Pocket MV.