John is correct that it's not legit to claim a mark, patent, or patent pending unless it's actually so. I am also sure a lot of people use these ruses and risk the penalties, as they are a pittance compared to the potenbtial benefit.
While I certainly advise reading up on the subject, doing your own research, etc., I also recommend using an attorney to file patents AND trademarks. The trademark search lists the attorney of record. Frankly, if I saw WidgetsRUs (or whatever) was self-filed, I would pretty much guess the person has neither the resources nor the inclination to litigate an infringement. When it has a lawyer's name there it lends credence that the claimant means business.
-- Gordon