How much ampere on the 5V port?

I have ordered an Arduino 2009 but could't figure out from the specs how much ampere the 5V port provides for usage?

If there is a wiki page for it, even better :) since I could not spot it

It will depend somewhat on the input voltage. Higher voltages at DC-in will cause the regulator to dissipate more power and be able to deliver less current. The regulator itself is rated for 500mA, so that's the upper limit. You can probably expect to safely get about 250mA under most normal conditions.

See this:- http://www.thebox.myzen.co.uk/Tutorial/Power.html and for a worked example see:- http://www.thebox.myzen.co.uk/Tutorial/Power_Examples.html