Here is an article about flixfamily: http://www.hackingnetflix.com/2011/06/f ... ounts.html
I envision the sub accounts could support genres and moods, too.One of the more interesting features of FlixFamily is sub accounts, which lets you setup different profiles for family members. You can password protect accounts, and also prevent kid's accounts from seeing "R" or "unrated" movies. I manage my kids account because even if I limit their Netflix account to PG or G movies, they can still see some pretty racy movie boxes. With FlixFamily the kid's account will only see movies in categories you select.
I emailed the developer and, as the article states, he is pretty receptive to ideas.