I found this in Active Brads Blog, Paying It Forward, Active Rain Style - 100 Links You MUST See! Thanks Brad!!!
This one I had to try out. I have tried several other sites to map multiple properties but this one does not require you to have an account to use it. This one also allows you to reorder the listings as needed.
Using this has made life so much easier when setting up multiple showings, even in different towns.
Just go to http://www.randmcnally.com/and click on the "Add a Stop" link to add as much as 10 locations. The best part is you get to see an overall map showing the location of all of the properties then you just re-order as needed to make your tour make better sense.
Good luck with it!