Just wanted to get the word out: Odeon Manchester, in the UK, are showing "Mirrormask" from Friday - I'm told only for one week, to make sure it qualifies for the BAFTAs, so I think it's the only place in the UK to see it right now.
http://www.thefilmworks.co.uk/index.php?page=whatson&tbx_site_id=11
(about 2/3 of the way down, under "March of the Penguins" and above "Polar Express IMAX")