http://www.mouse-house-tour.com my page
Kijiji.com (craigslist type site)
trulia.com (my page)
postlets.com (listings only)
Rapidlistings.com (my page)
Newcondosonline.com (my page)
Inetgiant.com (craiglist type) Massive spammers
Here is a list of a few other sites you can post your home for free:
There are many more, these are the ones off the top of my head that seem to be the most popular.
You've gotten some great advise. My clients who go on their own to rent out property have had the best response from Craig's List. The nice thing about Postlets is that you can use the html from that site in Craigslist to creat a high impact presence. Are you willing to cooperate with an agent working with a renter?
Craigslist is usually really good (as you already know). Have you thought about WestsideRentals.com?
Have you considered having a Realtor take care of it for you?
All the best!
Keller Williams Realty