Static server side listing

[Mark Constable]

I've looking for a solution for this and no amount of googling has
come up with anything.

Is it possible to provide a static listing on a server, say every
24 hours, that a standard end-user rsync can pull and use?

I have a lot of files to provide and the idea of every request
dynamically providing a file list in real time is killing my
server and is simply not needed. I am quite prepared to swap in
(atomically) an alternate file tree every 24 hours as long as I
can also provide a static file list. I know the files will not
change for 24 hours and could easily handle a 10Kb to 100Kb static
list being downloaded, plus the actual delta downloads, but adding 
100/sec listings of 20,000 files is a killer.