With D&D proper's Unearthed Arcana (i.e. the book of exceptions), there is a list of traits (which are both good and bad, so they don't cost anything), and flaws (which are like negative feats, so they give you a bonus feat).  Both are usually limited to 1 or 2 by the DM.<br/><br/>Surprisingly enough, all the contents of the book are on the d20 srd.