I love zenfolio.  Another useful option would be to allow viewers to mark their favorite photos.  I.E. Bride & Groom could mark which images they love and I could use those in the album design.   I believe instaproofs offers this.

I totally agree on that!
Also some kind of "voting mechanism" (maybe combined) would be super.
(like most sites have either thumbs up/down or five stars to set)

/patrick 

I would like to have this feature, too. Only question is how "Bride & Groom" should be identified. In other words, I need to know who tells me his favorits. I'm not familiar with the instaproofs solution.

One possible solution could be that a visitor adds images from one or several galleries/collections to a lightbox and after finishing he/she can send me the selection via email by entering his/her email address.

If we think it further the lightbox can be used for arbitrary features on images selected by visitors, like adding to shopping cart or bulk download. I love ZF as it is today! Anyway this would be a huge improvement for me.

Yes, it would be quite handy for people to be able to "Add to Favorites" while browsing their images.   I find that the more they add in the beginning the more they will buy, rather than "Oh,where was that one I liked...."

I'd like this feature!

Does anyone have ANY workaround to make this possible for the time being?  Asking customers for image numbers is just awkward.

If my customers had a way to somehow indicate what images they mark as favorites, I would be completely sold on this service.  Photoshelter has this ability, but at a much higher price.

I think you can create a visitor account for them and add a "favorites" collection to it.  Send them the username and password for this visitor account and have them log into it and then have them visit your Zen gallery.  Then when they visit the photos at your Zen gallery, they can add images to the favorites collection of their visitor account (it's in the photo menu.)

After they're done picking favorites, they can email you so you can see what they chose.

I suppose you could get fancy and put a link to their visitor account in your gallery along with instructions on what to do.

Bart