I have been looking for a user-friendly,AJAX-y web application to allow easy sharing of arbitrarily large files for YEARS. Finally,FINALLY,I found one –Relay.
Relay was a “dead project”that hadn’t been updated in several years,but my testing finds it perfectly functional. It was very difficult to actually find the code for it,because the web’s full of links to the original page,which is long since defunct. However,if you are persistent enough in your Googling,you eventually find that a Google Project was created for it several years ago –which was uploaded by someone with a now-defunct Google Code account. Luckily,I managed to get ownership of the project at Google Code transferred to me;so Relay is now available for download –and actively seeking interested developers to address a couple of issues I’ve addressed on the project page.
You can find Relay (and help develop it further!) at http://code.google.com/p/relay.