In Adobe Photoshop Elements 6.0, how do you; in an image, make some parts in colour, and some in black and white?

Not all together familiar with elements. But one way of doing it would be to duplicate the layer. Convert the lowest layer into black and white. Then selecting the top layer use the eraser delete the parts you want to be in black and white. Be careful though, because once you save it you wont be make changes like you would be able to with CS using layer masks.

Yep I've already worked it out, and thats exactly what I did! Sorry, I should have updated this thread, thanks for your help anyway.