OK, no one is responding, so I'll bite
.
Research is recommended for highly competitive residencies or for residencies in academic institutions known for research. So if you want to do neurosurgery, dermatology, etc, yeah, you should do research if you are not willing to relocate to any residency program in the country (are willing not to be choosey where you end up).
HERE ARE SOME COMMON MISTAKES MADE RE. RESEARCH:
1. Thinking you have to know what residency you will choose before commiting to a project and putting off research until late in medical school. Yes, if you already know what you want to do, it's best to do it in that field. But it is a mistake to put it off until late in 3rd year or worse, 4th year. You want to have time to contribute to a publication and be knowledgeable enough to to discuss it inside and out. At the very least, you ought to be able to say (while you are interviewing for residencies) that the "manuscript is in preparation."
2. Ignoring opportunities for publication that do not involve research. I am guilty of this, I cannot even tell you how many reportable cases (rare illnesses and conditions) I encountered in med school. What a fool! I should have offered to write these up! I could have had at least 4 publications going into residency, but I was "too busy" to put in the effort. Don't do what I did...
3. Signing up for a research project and not taking it seriously. A friend of mine did this -- basically, he took 6 weeks of research elective time and used it as a vacation (he thought he was in good with the P.D. and that the person he had signed up with to do research had no say in the acceptance of residents -- he was wrong, any faculty can blackball you). You have to work your butt off in a research elective. Consider it as a subinternship or an audition for an outstanding letter of recommendation. Even if you end up with negative results (ie, non-publishable results... hey it happens...), you want to get a letter from your faculty advisor that says you are the best thing since sliced bread.
OK, this is too long already. Good luck and let me know if you have other questions.