I've come across a great app that I think is very exciting, especially for photographers. It's called MapFlickr (http://www.imapflickr.com), but like many great apps, there's no way to embed on a Wordpress.com blog.
I guess a lot of apps don't have a wide enough appeal to warrant inclusion, but this is one I think has some legs in it. Would be great to have short code to embed the maps I create in my blog.
