I download lots of ISOs from MSDN and others for evaluating software, developing etc...To be frank, burning all these to CD is a pain. I have recently stumbled upon a great tool called Undisker - basically, it lets you treat ISOs like archives - so you can extract them to directories, as well as making whole drives into ISOs - incredibly useful surprisingly!
Anyway, it's a great tool and only costs $29.95 not bad considering that I reckon it's saved me a couple of hundred blank CDs in the couple of months since I started using it!