Photo2Cloud is a Windows Phone photo app that will back up your pictures to Skydrive, Picasa, Flickr, Dropbox or Box. Photo2Cloud backs the images up at full resolution and you can use as many accounts as you would like.
Photo2Cloud's set up is rather simple. First you set your permissions to the various accounts. Then you create mappings for all your syncs. While it's nice that you can set up multiple accounts the strength of Photo2Cloud rests with the mapping.
You can map your pictures backup for one Pictures Hub album with a unique folder on Skydrive and another album go to Dropbox. Or you can backup the same folder to all the cloud accounts at once. Or you can backup each folder to various folders on a cloud account. Mapping gives Photo2Cloud a good bit of flexibility.
The only downside, and I use the term loosely, to Photo2Cloud is that you can't set it to automatically backup your photos and only five photos can be uploaded in the background. I use the term loosely because this is due to the nature of the OS and not on the development end. The limited upload queue will let you leave that app and do what you need to do but eventually you'll need to return to Photo2Cloud to resume the backup. Instead of automatic backups, you can set a notification to remind you to backup your photos.
The nice thing about manually backing up your photos is that you can delete all the bad photos first to lessen the space needed in the cloud and minimize the data transfer. And while I wouldn't mind seeing the entire upload be run in the background, in having to return to the app (or have it running for the complete backup) you can see if there were any upload errors/problems sooner than later. In talking to the developer, there is hope that Windows Phone 8 will have more access and allow for more automatic uploads.
All in all, Photo2Cloud is a neat little app for your Windows Phone to backup your photos. There are some limitations due to the nature of Windows Phone but not to the point you want to run screaming from the room. And sure...you create a backup when you sync your Windows Phone to your computer but what if the computer dies? It never hurts to have a second or third backup source for your photos. Photo2Cloud offers you a simple way to create that additional backup source.
There is a trial version available for Photo2Cloud that is limited to five image uploads per day to give you a feel for things. The full version of Photo2Cloud is currently running $1.99 and you can find it all here at the Windows Phone Marketplace.