As I'm currently in the process of looking for an apartment, I'd like to suggest to anyone else in the same situation to definitely take a look at Padmapper. Rather than sorting through craigslist by text, Padmapper allows you to see individual rentals on a map of the area you are looking for.
Min/ Max Rent
# of Bedrooms
Min # Bathrooms
Max Price Per Bedroom
Max Age of Listings
It's got other neat features like Walk Scores for the apartment's surrounding area and a Commute Time Overlay. It also does pull information from more sites than just craigslist. I've seen a couple other renting sites have their posts displayed as well so it's not purely a craigslist tool.
One thing I'd like to point out is that people often do not put exact addresses when they create a listing and instead put approximate locations or just the two closest intersections. This isn't Padmapper's fault as it can only use the information it is given. So as long as you know that the locations aren't always precise down to the street address you should be fine.
If you'd like to read more about the site then check out their blog, PadBlog.
I really can't recommend Padmapper enough.