What can I do about the unsightly air conditioning units in my apartment?

Question

These things are brown and ugly. They are under every window. (Built into the wall) That can I do? They're hideous!

Answer 1

Is the problem inside or outside? Rust-o-leum makes a paint that uses the oxidation in metal to bond the paint. It's really quite amazing to be able to paint over rust, but it works well.
If the problem is in the plastic, interior parts of the units,soak them in bleach and water. (one quart bleach one gallon water)

Answer 2

As long as the landlord doesn't have a problem with it, paint them.