There are so many FTP mirroring programs – which should I use?

I have 2 WebDAV servers (one of which also runs FTP services on the
same share) that I really rely on.  These are not my servers, but
accounts on shared co-located servers which I pay premium prices for. 
 I use one for graphics and one for stuff like MS office documents.  I
use them as a central place to store stuff when collaborating with
others.

In order to get to my files fast, I have been mirroring these shares
onto 2 of my small file servers in my office (a windows XP Pro
computer and a MacOSX computer, both act as servers for our few Macs
and PCs).

One the Mac
On the Mac, I manually mount the graphics WebDAV share onto the
desktop, and use a killer program called TriBackup to mirror it to a
local folder that is shared .  It is a real drag to have to mount the
webdav share.

On Widows XP
One my XP box, I havn’t found something as cool as TriBackup, and I
don’t want to have to mount webdav shares.   There are tons of
programs (like WS FTP) that do mirroring.

Any ideas on a webdav compatible PC apps for Win XP to do my
replicating.   I want to set it to check every 3 minutes.   If someone
else from the remote group edits a file, I want to see that file get
updated in the mirror ASAP.


-Sherpa Jay