Looks cool. One question - is there a way for a client to mark images as favorites? Or ones they want to order prints? While I like simple, just looking without giving the client a way to do something with the prints may be cumbersome for them if they have to look through an entire wedding, write down the ones they like and then go back and look at them again...
For a small shoot it's prob not a big deal, but if you have 700 images to look through it would be overwhelming to a bride if they didn't have any tools tied in with it.
If you could tie this in with a way for clients to mark the ones they want, and then look at just those I think this would be something valuable for weddings.
I know you want it simple, so it's just a suggestion.
What you are suggesting requires a full blown Database driven Shopping Cart application. There are many of those available. I built this app for those like myself, who don't need a shopping cart application to display their proofs (or don't want to manage one or go to the effort of installing and setting up one) - and simply wish to have a good looking and efficient way to present a gallery of images to clients. That is how I present all of my wedding work to clients - with hundreds and sometimes thousands of images to view. The OnePageClientLogin proofing setup is DRAG AND DROP - making use of easily available Galleries like OnePageGallery, Simpleviewer, Lightroom Galleries etc - - - the different proofing galleries can even be MIX AND MATCH with these gallery apps.