In the browser, I found that 'left mouse down' is handled by double-tap-and-hold using the stylus; much like a laptop touch-pad. It works OK when you're personalising your Google homepage (www.google.com/ig) on the 770 (I went to the Apple Store on Regent's Street last night after work for the free wifi and was demoing my 770 to a friend who works at Google and he went on at me to go do all that! ).

You can drag the sections around and they save OK, but the same thing doesn't work too well in Google maps... I found I could zoom and center ok, but the dragging would only go a few pixels and stop.

In general the performance of Google Maps was pretty poor, but usable if you go fairly slowly. A variety of other sites I tried had generally good performance (rendering/scrolling etc).