will there be any plans to support page caching? - zp badly needs it

please don't use smarty - though it may seem good at first. smarty has its own templating system which wouldn't be used because of the theming already in zp. 90% of smarty wouldn't be needed for zp.

and does zp hit the albums dir on each page load? if so that's very intensive and ill thought out. could it be an option in the admin to 'update database' or something and the album dir is traversed?

caching html could be done in the database, storing the page as a record in a table, or as a file. this could be cleared from the admin, or expired past a certain date.

No plans for smarty, except for a user who wants to try experimentally. If that will be an option only.

Do you really have that many problems with the speed of zp? Yes, zenphoto is file system based. If you really need a caching system, we have some third party solutions here: http://www.zenphoto.org/2008/06/performance-hacks/

like acrylian said, check out the performance hacks page.
there's a 3rd party cache available for zp, supports both plain HTML and gzipped cache. it works, but has few rough edges.
I had also added some bits of code to minimize disk access, but you'll need to run some sort of persistent processes like eaccelerator, memcached. look at the bottom of the page.