On a side note, tell your landlord to look at having Simplex or simplex style locks put in the main entrance door. They're push-button combination locks for doors.
Then he just has to give out a code instead of a bunch of keys.

It won't stop people from giving out the code to friends/family (or stop someone who really really wants in), but it will stop someone on the street from just casually walking right in. Which, is basically what you're looking for here. They range in price from $200 to $800 depending on security level and style, but they're worth it when the other option is leaving a door completely open.


You may even be able to take up a collection in your apartment building to have it done, then all you would have to do is get the land lord to approve it.