Not on Trulia, you can't as Trulia does not allow FSBO (For Sale By Owner). As the other agents suggested, there is a lot more to deal with on a Condo, like the financing section.
Another option for you would be to contact a brokerage that does a flat fee listing. There are several out there that charge a flat fee, like $499 and all they do is list it on your local MLS. This will generate traffic, and it will auto feed to sites like Trulia and it will be listed. I do have to warn you, you would have to do all the paperwork, negoate the deal yourself. Just like a person is free to represent themselves in a court of law, for most people hiring an attorney will be their best bet. Wanted to provide another option for you. Here in Tucson, AZ 91% of all properties are sold thru the local MLS, it really is the best way to sell a property.
Best of luck.