I backup my photos in the cloud using Ubuntu One. I would like to view them in an online gallery in a browser (like Dropbox, which has a "photos" folder). Is this possible?
Not yet, but you could request the feature here:
Make sure you mention that it's a feature request and that dropbox already provides this functionality.
The beauty of the free and open source community is that you can request for a feature and actually expect an intelligent response!
Since I couldn't find any feature requests like this, I created a new bug report and hopefully one of the developers picks it up so we can see this feature in a future Ubuntu One update.
Please subscribe to the bug here: https://bugs.launchpad.net/ubuntuone-servers/+bug/1036488