Many approaches could work. If you don't care about it being instantaneous, you can do a cron job to sync it. With this approach you could use rsync, which would take care of the syncing and would only copy the files that are new or need to be updated.
If you need instant sync in the same moment that you save the file, then inotify is the way to go, if you have the inotify tools installed you could do something like this:
inotifywait tmp/1 --event create --event modify --format=%f --monitor \
| while read filename
cp --force "$filename" /some/other/directory/
Untested, so make your checks and make sure you understand the snippet before you use it. Another matter would be how to launch this, if your distro has some kind of file to launch custom scripts at init, you could run this from there (i.e. /etc/rc.d/rc.local or something like that, in Gentoo we have /etc/conf.d/local.start). Wrapped into a
su your_user_name -c '<insert the above snippet here>'