downloading 'boot.img' while using fastboot to copy ra recovery
At the time I was semi-blindly following another poorly written walkthrough that just had a series of commands without explaining them.  Now with some knowledge I eventually worked out that it was better to flash the image to the phone.  Still don't know why it was taking so long though.

Eventually with flashing to the phone and then the Cyanogen Mod, I got it all working.  Now with ROMManager on my phone it'll be sooo much easier in future!