I have a page which uses a scrollable
There is no easy, native way to make divs scrollable with one finger, as if it were a full screen panel. You can use two fingers like Andy E says, however I doubt whether most users will know about this, and it's not very discoverable IMO.
Sencha etc can do it, however it's not real (i.e. native) scrolling, it's using all sorts of Javascript trickery to approximate it, and is liable to slow down and behave badly if you're doing anything else complex...
That said, web apps like Yahoo Mail on the iPad seem to make it work quite elegantly.