Sure, charge it in another device or charge it with a separate battery charger; you can get them for cheap.
My Cousin have a dead ( broken screen ) NOKIA 5800!! i charged the battery with him and!!!
I RECOVERED MY NOKIA N900!! and now i have 2 batterys for me jajajaja.
thanks to all.
I love my n900 every day, more and more and more!!
other phones just sucks xD