Click here to read a very informative article written by David Davis, a trial consultant in Boston. His article titled "Some Juror Rules for Determining Damages" summarizes research conducted by economists at several universities relating to how jurors perceive damages at trial.
The most interesting portion of the article is that specific numbers seem lower than round numbers. For instance, $325,425 seems lower than $325,000 at first glance to most people. The author recommends asking for specific sums from juries for all types of damages, including punitives. Even if you are just making the number up, do not make it end in zeros.