I got a Qnap NAS a few months ago to store stuff on my network. Searching around I discovered a blog posting on how I could wire up time machine on my mac to back up to my NAS, without buying the very nice wireless time capsule that Apple make.
It took a wee bit of jiggery pokery, and a good bit of knowledge of the NAS and a bit of tweaking on the mac, but it all works seamlessly now. Sorted.