This is sort of the spawn of the Small Isles thread I started a few weeks ago.
I think I've got six nights to spend on the Northern Isles, which is what I'm calling Westray, Papay, N. Ronaldsay, Sanday, Eday, Sapinsay, Stronsay, and the like. We've explored most of mainland Orkney on a previous trip (although we missed Stromness) but did catch Rousay. We would probably use LoganAir for most hops, as they seem very inexpensive and quick. I'd probably opt for a Westraak tour on Westray and a Peedie tour on Papay to eliminate the need for transport headaches. There appear to be similar arrangements on at least a few of the other islands.
We can't see all the above islands in the available time so I'd love if someone could slash the list. We're most interested in birds, Neolithics, and scenery, and less interested in shopping, museums, beaches and lighthouses. This will probably be our last trip to Scotland, so I can't just put things on the back burner for the next trip.
We travel very light and it's not unusual to spend single nights in a location, although I've been moving to multiple night stops more recently. The remainder of the three week trip will be the Small Isles, Uist(s) and Barra. I did manage to decode the Small Isles schedule to visit all four island in five nights (two on Eigg).
So many islands and so little time!