Okay, to install ndiswrapper I need to do 'debian/rules binary-modules', that requires the kernel source code.

Now, the thing is, the installation guide which for ndiswrapper on debian tells me to apt-get the headers and to find out what kernel headers I need I do "COLUMNS=200 dpkg -l | grep kernel-headers-$(uname -r)"... for a start, I've googled and have not got a clue what that actually does. But more importantly, it doesn't seem to do anything... it runs, but I don't get the name of the headers needed. if I just do "COLUMNS=200 dpkg -l" I get a list of a whole bunch of stuff, but thats not of much use.

I'd really appreciate knowing what I need to do... have I entered the command in wrongly? I've tried many different variants but to no avail.

Just type 'uname -r' that will give you your kernel version. Then you need to install the kernel source for that kernel and also the kernel headers for that version. Should be able to simply apt-get them.
Good luck.

Well, here's a big thanks in capital letters... THANKYOU! Will try it in a mo, that had me scratching my head for ages