well i would like to add here........

Actually the needle can float as well as sink in water.......

U can do the followin experiment at home also(tested myself)

take a mug full of water.....dont disturb it ..(dont shake the water, let it settle down without any ripples..)

Now take a tissue paper only one layer of itand precisely a small cut piece of it...small enough to accomodate the needle...(only tissue not any paper) and place the needle(not necessarily greased) on top of the tissue paper and slowly place both the tissue topped with needle into the water so tht both of them float....now after the tissue paper is soaked with water....take a sharp thing( like a pen nib or something) and push the tissue below the needle into the water mug and make it sink...(here care must be taken in not disturbing the needle.)..

NOW SEE FOR URSELF THE NEEDLE FLOAT ON WATER.....it will continue to do so as long as u dont disturb the water or the needle.

Thus we can proove tht surface tension balances the needle and it stays floating..

~Cheers