I'm not sure what other brokerages have a feed with Trulia, but Prudential California Realty does have a relationship and posts all of their listings on Trulia...it does take a few days for them to get posted. Good luck selling your condo!
Both of the answers below are right on. Your agent or broker can submit your listings to Trulia via the options Christopher mentioned below or at the link below.
Customer Service Representative
Did you ask your agent before you signed him or her to represent you where your home will be marketed on the internet?