I had 7 research citations to list on my CV (1 poster, 2 presentations, 4 pubs). They didn't really seem to care if the research was published or not, and actually I was asked more questions about the work which wasn't yet published and still ongoing than the work which had already been published. Maybe because it was more cutting edge?...I dont know for sure. But I was definitely asked about most every project at every single place I interviewed.
I think this research went a long way to help my less-than-stellar step 1 score which I've mentioned in earlier posts, and definitely provided plenty to talk about in every interview....no awkward pauses. I would agree with the sentiments expressed above that research isn't necessary, but it certainly helped me to stand out more than I would have without any research.
To answer Leisure Suit's question about listing ongoing research, if it's been presented at a conference, then you can definitely list this. If it hasn't been presented yet, I'm not sure I remember a place specific for that on ERAS, but I know you could squeeze it into some random text-box somewhere in the application even if it doesn't necessarily belong there (maybe under "Activities" or something like that). And certainly you can bring it up in interviews whether or not you listed it in your original application. Like I said, they didn't seem to care if it was fully completed or not as long as you knew it inside and out, and had a perspective about where it fit in to the big picture of orthopaedics. Hope that helps.