I've really enjoyed Dropbox paper for meeting notes & collaborative discussions. It's clean, simple, and quick & easy to share with several members of the team.
Recently I needed to make a simple brand guide for my company, and decided I'd try to make this in paper. If I was able to create columns, and/or write descriptions below photos, this would have been a perfect fit.
I've also played around with Invision Boards for this, but I need something that I can export as a PDF, which Paper can do (thumbs up!).