Other than the mentioned advice of going to office hours with a purpose, I would say a golden way to get your professor's attention is to read their papers (select the top k most cited/interesting/whatever heuristic works for you). After doing that, you will undoubtably have focused questions to ask that can lead into discussion that will implicitly signal to the professor your interest/curiosity/passion (don't bog yourself down in the low level details). Reading papers is good practice anyway if (a) stuff like independent study intrigues you and (b) you want to stay current within your field of interest.
Thank you, that seems like great advice. A few of his better known papers are definitely over my head currently, although I'm familiar with the basic concepts at least; but luckily he has some other work that is at least somewhat accessible for where I'm at. I'll keep working through his stuff and come armed with some questions, and as you point out, I can definitely use the practice in being able to read papers well and stay abreast of things.
