I happened to get a PI that allowed me, in time, to do a lot more hands on experiments--injecting the drug we were investigating into chick and mouse embryos, sectioning tissues, in situs to determine genetic pathways.
I agree with Ilovehedgehogs. I think a lot of the quality of your experience has to do with how proactive you are. I was in a lab with 6 other lab techs, and for some reason (at the risk of sounding conceited.. I really don't mean to, honest..please forgive me in advance) my PI seemed more impressed with me and gave me more responsibility than the others, which eventually led to coauthorship on a paper. Looking back, I think it was because I expressed more of an interest--I wasn't getting paid like the other lab techs and sought her out. I started presenting at journal club and lab meetings. And when I had ideas I wasn't afraid to tell her. I followed postdocs around when they were doing animal surgeries, and watched, and then asked if I could practice on the few remaining embryos that were going to be discarded.
My sister also has had good experience being proactive. She told the researcher upfront at her interview that while she was perfectly amenable to doing scutwork, she ALSO in addition wanted to have some responsibility, and be on a project that would eventually be published. She of coursed phrased it as politely as possible, but the PI was receptive. Then she started showing up at lab in her downtime even though they didn't have anything planned for her to do. In time, when she was there enough helping out on her own time, they gave her mini experiments, which led to larger and larger experiments.
Also, if you're still a freshman, there's plenty of time to get both clinical and basic molecular research experience. If at all possible, I'd try to get both by third year. The clinical data entry doesn't sound *too* time consuming, so maybe you could do a molecular project on the side. The best of both worlds would be to find a project that combined both---was molecular in terms of experiments etc, but has real clinical significance (e.g. has direct relevance to some sort of disease). Then you could tie it all together by going to shadow physicians in the hospital who treat people with that disease, and possibly find doctors who were doing clinical research on that disease. It's not necessary that they all relate, but it sure does make for a lot to talk about during interviews, and gives you a really cool, comprehensive perspective on a particular disease that not too many others will have.