There are a lot of lightbox scripts floating around out there, and it's tough to choose a good one. I'd be leery of one like prettyPhoto, which hasn't seen any activity in almost seven years, and whose support forum is broken and inaccessible.
And that's why I can't recommend that anyone just adding a lightbox to his website use Highslide JS - you don't want to hitch your wagon to a meteorite that's plummeting towards the ground. If you have questions, or need to get a bug fixed, you may find yourself with nowhere to turn. I'm not sure why I stick around here - there's no fame or fortune in it, that's for sure.
When not coding, I'm a retired guy, and I
travel a lot.
When coding, I'm doing
skins for jAlbum. The oldest two (Matrix, MatrixSlide) are based on Highslide JS, along with one newer one (Comet). A couple of the newer ones (Saturn, Neptune) are using
Floatbox- that's current, full-featured, and well-supported, but not free. I've also got one skin (Gromit), and another one in beta, that don't use a lightbox at all - separate pages for each image (people who fret about SEO like that).