Wanted: good photo-management web site software

Having returned from vacation with a ginormous collection of beautiful photographs, I’m once again confronted by the out-of-date complex nonsense that is the photo album software on my web site, “powered by Slooze”.  (The name kinda says it all.)  The effort required to tag and resize my images, upload them to the site, and load them into the Slooze database makes me feel tired just thinking about it.  What I need is a nice free drag & drop package, that can handle such things as generation of thumbnails, uploading of images and/or directories from my brower, and (preferably) a nice front end for my visitors.  Any suggestions?