Penthouse for sale! This prewar gem features prime Upper East Side location, four bedrooms, five bathrooms, library, and quite possibly the chance to see Bernie Madoff in his Underoos:

Reports say brokers are already visiting the hedge fund hustler's penthouse with an eye towards putting it up for sale to pay back creditors. But Bernie is, you know, on house arrest at the moment, in the apartment. Which gives you a good reason to go take a look at the place!

Because he must remain inside the two-story apartment as a condition of his $10 million bail, Madoff will be in awkward proximity to brokers when they eyeball its four bedrooms, at least five bathrooms, kitchen and library.

"They'll probably have him in the dining room when we're in the bedrooms and vice versa," said the broker.

But not if you're a disgruntled investor packing a gun. Others welcome. [NYP]