Offer streaming sources and prices like Reelgood & Apple TV
Hulu Plus is often overlooked, but it has quite a large collection of classics and Criterion films that are not available on Netflix (and others).
This might be a stretch, but sites like moreflicks.com have access to the list/links for all netflix regions. Now I know that because non-US Netflix accounts don't have the Instant Queue you couldn't add films globally available to your queue through Letterboxd BUT there doesn't yet exist a way to check availability on all Netflix regions.
In a nutshell - because of the ability to switch between Netflix regions online, I'm looking for a way to sort films in Letterboxd by availability not just in US Netflix but in UK, Brazil, Sweden, Canada et al.