SIMR is an awesome research program, I highly recommend it. I participated in 2012.
The website ( Program Description - Stanford Institutes of Medicine Summer Research Program (SIMR) - Stanford University School of Medicine
) covers the basics: its an 8-week program hosted at Stanford, youre paired with a grad student/postdoc mentor and perform biomedical research with their guidance. As with all research programs, your experience will depend on your mentor and project, but on the whole people liked their mentors and projects. There are some morning lectures where profs talk about their research & careers in science (these are really good), and some institute-specific lectures where grad students talk about their research.
SIMR is extremely competitive: this last year they took ~60/1200 applicants, a 5% acceptance rate (lower than any undergraduate college). Most people there have good stats; a good portion have previous research experience; some are extreme overachievers [[[a few have done very well in science fairs (one was def intel semis), academic contests (USAMO quals, I think one particpated in IBO), and one person I met has ~1,000,000 users for his iphone apps/games. ]]]
Most SIMR students were more good-all-around students, you dont need a nobel prize to get in. However, you do need a compelling application. This is not all stats--your essays are extremely important!-- and they encourage diversity, so if your essays show you have a burning passion to do research/unusual life circumstances/compelling reason why you want to study medicine/your essays are just amazing and makes the director really like you for whatever reason, you dont need a 2400 SAT or whatever to be admitted. If youre URM/underprivileged that is a definite plus. (However, note that a large majority are not URMs or underprivileged, most are asian/indian with well educated parents, you dont have to be diverse in a traditional sense to get in. If you are stuck on the diversity essay, try writing to the prompt what makes me unique/special.)
Most SIMR participants go on to top schools (#1 destination Stanford, #2 Harvard). A few get author on papers if they are lucky and have gotten a lot done; some do very well in science fairs. Bioinformatics/computer projects tend to get results more quickly (good for science fairs), but the results you get varies widely based on your project (research involves luck), so sign up for whatever youre interested in. (If you hate programming, you dont sign up for bioinformatics).
One note about the social atmosphere: you have to take the initiative to get to know people. If you do so, it will make your summer a lot more fun! People are scattered across the med center, and there is no central meeting time/place for lunch. Some people basically go to lab, eat in lab, leave lab, rinse and repeat. However, if you attend the optional weekly social events, and you make an effort to meet other interns during lunch and get to know them, then you will make a close group of friends and have a great time. Most of the interns are pretty cool, socially competent, incredibly talented, and fun to be around (assuming you like being around smart, motivated people)-- take the time to get to know them!
Notes on demographics (these are rough & from my impression/memory):
I would guess ~15/60 were minorities in 2012; most of the rest were asian (including the subcontinental variety, which some prefer to distinguish as indian).
Gender ratio was pretty balanced.
Most interns were juniors/rising seniors (say 75%?) while only ~?25% were to-be-college-freshmen.
Most interns received $500 stipends.
Most were from the bay area (well over half, maybe >75%).
Note if you need to get housing: it is expensive! If youre 18 you can apply to live on campus which costs $2500-$3000 for the summer, off campus is similar.
If you are choosing between SIMR and SHARP Ill make another thread with the key differences (I did SHARP after junior year and SIMR after senior year, Ill be a frosh at stanford in fall 2012).