Can't find the thread, but thanks muchly to whoever pointed me at Cheese to get a CCTV onna stick thing working, and not least because I've just been given an old microscope USB camera which the donor insisted worked OK on Win 98, but the software wasn't compatible with XP, and when I told him that I intended to use it in Linux, his anticipation of success dropped to zero.

He was most surprised when it worked in Cheese without demur. I hope to proselytise...

So, thanks again for the pointer.