Has anyone tried these
 

Has anyone tried keyworddiscovery.com? Is it worth the subscription or are there free versions out there that do the same kind off thing?

AndyS,
I'm not sure exactly what you are looking for but this is what I use for most of my kw research:
http://www.digitalpoint.com/tools/suggestion/
I also use old server stats. It takes a little bit of time but if you dig deep enough intod digital point you can usually make a good list. It's free :)