Take a look at http://fotopic.net/ They have an API which lets you link into galleries hosted by them. Individuals can also get free galleries. I know they're popular with outdoor folks and have used them myself. Not connected with them, just a satisfied user.

Chris

Thanks heavens I've got 1mb Broadband, all of those thumbnails for the Expoor 100 presented in one go took ages to download, heaven help anyone on a 56k dial up connection.

Having made 3 posts this morning on my first visit to the site all commenting on design & performance issues, I don't want to be too critical but take a look at CopperMine
http://coppermine.sourceforge.net/ or http://gallery.menalto.com/ which are both FREE and would fit into the existing design with ease, not too mention providing many more features...