A relative of mine loves Google+
You are supposed to be able to download full file sized images from it.
I've tried downloading from there and it is a little slow...you need to click on the image then pick the file size, etc.
Loading images onto the site seemed really slow to me.
I don't think that most sites allow you to save and download full file sizes if you have big image files....a 12 megapixel camera for example, you may not get the full size file back on download.

Sorry I can't be more help.......

Almost every team we've belonged to has used the Shutter fly site. It's my fave and I'm picky. It is easiest to use and picture quality is great.