Google maps uses a custom cursor to implement a grabbing hand. When you mouse over a map, you get a little hand custom cursor. When you click the map, a grabbing hand custom cursor is used.
On WebKit, the cursor isn't updated until a mouse move. A click and hold is still left with the hand cursor until you start to drag, which then updates to the grabbing hand cursor. Firefox and Internet Explorer get this correct and update the cursor on click.
Seems like it would be simple to fix. I actually see maps.google.com turning back to an arrow on click, and then flipping between an arrow and a grabbing hand on move.
Hmm... Eric, do you see that cursor flipping behavior in Chrome? Using both trunk and release builds of Chrome, it seems to only have the problem that Dean reports.
See also: bug 17052.
*** This bug has been marked as a duplicate of 14344 ***