The old tradition was to call it 'Trex'. Something to do with Speverend Rooner and looking for the cooking fat... In half the photos it looks like a British Blue. My friend has one called Sybil (Basil died,sadly). What about "Trillian"?
Yes, she's a mog but the rescue centre said she had "some British Blue" in her. Reading descriptions on the web she seems to fit them very well!
We seem to have settled on "Felicity", or "Flisstycat" for short - but we're not sure if she'll get use to it. If she won't shed Cuddles, we might have to make her "Professor Cuddles"...