Parking. Make sure you pay close attention to the parking signs. DOn't think you can get away with parking illegally for just a few minutes. Towing companies are paid by how many people the tow, so they are usually just around the corner waiting to tow you. It's pretty expensive and a big hassle to get your car out of the impound lot (~ $150). I've had a sister that was parked for about ten minutes in one spot and was towed. WHile they were trying to figure out what happend to their car, another car illegally parked in the same spot for a few minutes and was also towed! Two cars in a half hour from the same spot.
Also, be careful of the rates that the downtown parking lots charge. A lot of the rates posted are only 'early bird' rates which only apply if you park before a particular hour of the day.
The best bet for parking is the Monroe parking lot below Grant Park (between Madison and Monroe and about a block East of Michicago Ave). The rate have recently went up, but it's usually ~ $8 for all day parking. The Grant Park lot (about a block closer to michigan) is similar, but it costs a few dollars extra. I always park the Monroe lot since it's cheap, for the entire day and is a self park lot.
Beware of extra-wide parking meter attendents riding their Segway.
Would it really hurt them to walk a bit?