I've been doing undergrad research for a little over a year now, and I have two papers under my belt: one as co-author, and one as first-author. If you get publication of your research, then by all means, bring it up.
However, just because you did "research," doesn't actually mean you did something significant. For instance, many undergrads come to the professor I'm working under, and ask to do research. She (my professor) puts them to clean trays, input data, and do various errands. Now if these same people, that were just doing errands, happen to be applying a professional school, and stated that they have research experience in their applications, they wouldn't be lying. However, to what extent do they have research experience? Listing something in your application is fine, just be sure you can back it up comes interview time.