Can you use rockbox on the 4th Gen Nano? I'm pretty sure you can't, but hopefully I'm wrong...

I've been reading and digesting an awful lot of information from this site over the last couple of weeks so now it's time for my first post - and it's a question. I have an 80GB iPod Video 5.5 Gen and Shure SE530's and listen whenever I can wherever I am to lots of different types of music...