Hi Peter,
You can look at the examples in the repository by browsing to: http://code.google.com/p/raphaelgwt/source/browse/#svn%2Ftrunk%2Fsamples
Alternatively, you can check out the code using svn and run a demo to see it in action:
# svn checkout http://raphaelgwt.googlecode.com/svn/trunk/ raphaelgwt-read-only
# cd raphaelgwt-read-only/samples/dnd2
# GWTPATH=/path/to/gwt-2.4.0
# ant devmode
There is no zoom/pan in any of the samples but you're welcome to contribute one. :-)
Geoff