Rejected as well; http://pivotal.ws
Personally, I'd love to use this if it can provide context to my photos. No one gets context right. Couple that with discovery and you have a winning proposition. I don't think the rejection has anything to do with the product itself. I reckon they got a lot of applications this year they wanted to fund that drowned out a lot of the other applications (such as mine, to ally different story though:)).
Originally had planned this as an app but took the idea to a startup weekend competition (we won) and mentors there were pushing me to find a monthly revenue model.
Now that YC has came and gone I may revisit simply building this as an app.