Give each developer a hardware budget equal to the value of a top of the line MacBook Pro 17"....but each developer 'chooses' the 'laptop' he wants to buy (be it OS X, Windows, or Linux).

- the developer gets the hardware he wants to work with

- the developer feels a sense of 'ownership'

- the developer respects you for allowing him to choose

Mandate laptops because you super-awesome-change-the-world startup is going to inspire your developers to work hours outside of the office, even if you do mandate 8-5 office day.

Every developer gets two monitors, no exception.

You can't encourage a person to be an Olympic rower by simply providing a stool and a stick to paddle with.