I want to confirm that Trulia does not currently accept For Sale by Owner listing submissions. If however you are working with a flat fee agent or broker, that person can submit your listing to us via http://www.trulia.com/submit_listings/
I should also note that attempting to post a FSBO listing on Trulia through Postlets is not a good work-around. Any such listings submitted to our site are removed promptly and those who submitted the listing information can face other consequences due to their violation of our Terms of Service. Those terms require the person submitting the listing to warrant that they are a licensed real estate broker or real estate sales agent who has authority to enter into this agreement and submit listings to Trulia, and they must accept these terms whether they submit their listings directly to us or through an aggregator like Postlets.
Please let us know if you have any other questions or feedback about this.