I would most probably be looking in some simple PageData collection grouping and then iterating over group keys. Such groups are pretty easy doable in Linq. You may end up with double repeaters: one for group keys (distinct values of Division property) other for pages itself. Don't think that would be simpler approach :)
I'm using a repeater for a listing (of pages). The list consists of posts/pages and I'm using the property Division for heading (they are sorted by this property). Since I want the heading only to appear once I've come up with the function below. It works but I wonder if there is another (more simple) way to retrieve a property and only display it once (first time when sorted) when using a repeater?