UKDistributedView and UKFinderIconCell provides a very flexible icon view.
More precisely, UKDistributedView is an NSTableView-like class that allows
arbitrary positioning of evenly-sized items. This is intended for things
like the Workspace/Finder's "icon view", and even lets you snap items to a
grid in various ways, reorder them etc. Finally it can handle several
thousand of items smoothly.