Is it possible to backup photos to the cloud?

To any service like Dropbox or Flickr. And delete the photos that have been backedup.

I know there is Hyperdrive to backup photos, but if I understand correctly, you can't delete photos imported from the camera connection kit and you can't upload files of your choosing to a cloud service.

Is there a way to do this, jailbroken or not?

I found that I can delete photos imported from the camera connection kit, but uploading to Dropbox and Picasa, you can only do one photo at a time. Is there some app/service that lets you upload all photos in folder?

Well, the photobucket app lets you load photos from your iPad directly and although it does not give you the option to select an entire album or event, it is very responsive and quick when you start tapping on one photo after another within an album or event.
For instance, I just started to load photos from an event I had on my iPad of 30 photos and I simply tapped on each photo as quickly as I could and it loaded each one within 2 or 3 seconds. I don't have Dropbox or picasa, so I can't speak for their features.

Also, I'm not 100% sure if you delete a photo from your source (computer or iPad) if photobucket (or any other image hosting site) will keep them stored. I would guess it works ok, but don't quote me on that. Test it out to be sure.