I, like Mr. Hutz above, was surprised by the ease of getting recommendations even though I tend to be quiet in class (I was even offered one by one of my profs, go figure!). I also second the advice to try to take a class in the fall with a prof you have had before. You can ask them for a recommendation at the end of Sept or in Oct after having been an active participant since the beginning of the term and that is how they will remember you and write about you. Go to their office hours, chat with them, give them your PS, DS, statement of purpose, resume, papers you wrote for them, whatever you think is appropriate. Talk about your goals and experiences. Chances are if your work product was good they will remember you (even if it takes re-reading it). Being quiet is not the kiss of death for LORs!