SyncToy can sync the Access db as long as you do not actually have it opened and locked. Keep in mind this is really not the most efficient way of replicating Access databases as it would copy the entire database file every time a change is made and in the event you made a change on the other side you would not have a gret conflict resolution policy to merge the changes.
If you want something more effective you might check out the microsoft sync framework. There is a good webcast (if I say so myself :-) on the Access sync topic here.
Liam