Here is one thread with suggestions: There are probably many more, http://fineartamerica.com/showmessages.php?messageid=1121216
Flickr is a good option, They give you 1 TB of free storage,,,You can make the photos public or private,,,It is user friendly too, If you choose flickr make sure to download the flickr uploader which will do a great job to expedite the process, It is really neat, I export my tiffs to the desktop as jpegs for upload to faa. I have a Flickr folder on my desktop and drag the jpegs to that folder and the flickr uploader automatically will upload the images, It will not upload duplicates ,,,(The Flickr uploader will not upload raw Tiff files) ,,,