I've seen in the past, a 1Khz tone generator built into an XLR plug, now I need one I can't find one anywhere! does anyone know where I can buy one from?

Try This Linky

I dont suppose one exists that outputs pink noise instead?

EDIT: found the "Avlex Pink Stick" which looks rather good!

I've found several that emit pink noise but very few in the UK try www.orchid-electronics.co.uk

Does anyone know how the 1k tone generator works? Or how it would be possible to make one?

Canford Audio... it's 700Hz, not 1kHz and the price might seem a little steep ;-)

You could always go for this - http://www.behringer.com/CT100/?lang=ENG Switchable tone generator between 1KHz and 440Hz, just connect to whatever cable you need! I think they are about £30 and you get a cable tester too!!

Thanks for the assistance guys, I was hopimg to get the XLR type but although every other country does them for the equivalent of £15-£20, they cost <£36 here, I did find the CT100 earlier and it is very favourable at £16 from studiospares! I've mailed a US company who I'm hoping will be able to supply an XLR for about £25 all in, if not I'll go for the CT100!