Great series of maps for residents and tourists. Very detailed but extremely compact (though still legible), laminated, folds easily. It can be used quite subtly, so you don't look lost (giving the apperance of a goofy out-of-towner, or worse, a safety issue.)
Chicago Streetwise features:
-Main map (north to Lakeview, south to Hyde park, west to Ukranian Village)
-Downtown map
-neighboring counties road map
-Hyde Park/Kenwood detail
-CTA/Metra train lines
-street and landmark index
On the main map, it identifies train stops (but unfortunately no busstop info, which may be helpful), street numbers, various important buildings (landmarks, colleges, some hotels, etc.).
If you are planning on visitng Chicago, or have just moved to the area, look no further than this map.