If you were holding off on getting the black iPhone 4, for a white one, you are going to have to wait a bit longer.
Apple has delayed the white iPhone 4 again to spring of 2011. But, you might even want to hold off on that, as Apple may release an updated version of the iPhone 4 in the summer.
UPDATE: There is a rumour that the white iPhone 4 will be cancelled all together.
Image iPhone 4 White Available Mid July Originally uploaded by Photo Giddy