I found only one
http://www.panasonic.com.au/support/downloads/license.cfm?FileID=488&CategoryID=2&ProductCode=NV%2DGS400
Note, that this is for the NV-GS400GN.

Mine is the NV-GS400GC. I don't know what the differences are to the other versions - maybe just the power plug and language.

When Panasonic UK posts theirs (for the NV-GS400B?) I think it will be here
http://www.panasonic.co.uk/customer-Support/download-centre.asp
It's there for the GS200 but not yet for the GS400 (sigh).

I want to print a smaller version of the manual - one that will fit in the camera bag. Canon already knows this.