Television as Brain Food
There are enough Spanish speakers in the US that if you have cable television, you probably have access to at least one Spanish-language channel. If there are no Spanish-language channels in your area, search the Internet for video podcasts and online television programs. These channels and programs are priceless for working on real-world Spanish listening comprehension skills. Spanish-speakers on television speak fast, make puns, and use popular (but grammatically incorrect) idioms -- all things that people do in real life, but usually not in Spanish class.
Scan through the listings for your local (or Internet-based) Spanish channels and pick out a few programs from different genres. Your goal should be to expose yourself to the broadest spectrum possible, from Latin American youth culture to Cervantes-era classic Spanish. Each different program and channel will have speakers using a variety of Spanish accents, expressions and even mannerisms; try to catch a range of popular genres such as comedy, news, talk and sitcoms or "novelas." If you have access to a DVR or on-demand programming, all the better.
Try to spend at least an hour a day watching the programming you've selected, even if you have to fit it in while you cook meals or clean house. Keep a vocabulary journal and a pen nearby and jot down any unfamiliar words as they come up, but don't go running for the dictionary. You can worry about exact meanings later; for now, just let the unfamiliar words flow over you and focus on catching the gist of the conversation. If you find yourself getting frustrated about not understanding the words, set the vocabulary notebook aside and just watch and listen.