During undergraduate, most of the focus on graduate school admissions was for Ph.D. programs, for which there are fairly standard ways of making oneself competitive: get great grades, do a thesis with a well-known professor, get to know a couple of teachers to have good recommendations, and get an 800 on the quant portion of the GRE (with an emphasis on research and recs). During the time between undergrad and grad school, what can I do to make myself a competitive candidate? Furthermore, what do master's degrees admissions emphasize in contrast to Ph.D. programs?

I am particularly interested in a few "elite" programs--not because of their brand name, but because I constantly see "great" minds in the field come out of there. I feel being surrounded by such people would give me the greatest return. Specifically, I would like to apply to the MIT Media Lab and the Stanford Symbolic Systems program. So, for another point of discussion, should I work as hard as I can to make myself a great computer scientist, apply to 10 or so solid schools, and hope I am accepted by one or two of the best ones? Or should I focus my goals on what a specific program values?

EDIT: Related thread: http://news.ycombinator.com/item?id=422773