The following is a list of some fellowship opportunities that are available to graduate students in the molecular life sciences.  Some of the fellowships (such as the NSF Graduate Research Fellowship) can be applied for as a senior undergraduate. Many fellowships allow you to apply more than once, and others are best pursued as a 1st or 2nd year graduate student, so this process can continue once you're in a particular graduate program.  Some are targeted to particular types of research.

• National Science Foundation Graduate Research Fellowship
• NIH: Predoctoral Ruth L. Kirschstein National Research Service Awards (NRSA)
• NIH: Predoctoral Ruth L. Kirschstein National Research Service Awards (NRSA) for Minority Students
• American Heart Association
• National Defense Science and Engineering Graduate Fellowship
• Ford Foundation Diversity Fellowships
• NASA Harriett G. Jenkins Predoctoral Fellowship Program
• Dept. of Homeland Security Graduate Fellowships
• Department of Energy: Computational Science Graduate Fellowship (CSGF)

Another useful resource for learning about funding opportunities for training in the sciences is GrantsNet.