Hey gang, uploading photos to Flickr, etc. is super easy -- anyone you want can see the photos. BUT, what if you are on a trip with 4 friends, and you all want to share photos with each other? Are there online services that provide free photo sharing where *multiple users* can upload to an album? If security is a concern, maybe only the 4 specific (registered and signed in) users could upload new photos - email addresses or usernames designated by the mod... Is there any site out there that does this?