I would imagine that the use Mayan numbers on house decorations would
be a little similar to the occasional use of Ogham in public in
Ireland. Some years ago Dublin Airport had a set of banners
(http://www.evertype.com/standards/og/aerogham.jpg) which read
"DUBLIN AIRPORT" in Ogham. "AERFORT ATA CLIAT" might have been more
authentic -- though since one day I hope to raise an Ogham stone
which says OM MANI PADME HUM, I can hardly complain. Heh heh.

Anyway if they use the numbers correctly, that'd be nice. One
suspects that the postman doesn't make use of them, however.

For those of you using Mac OS X, the good folks at Wündermoösen
(http://www.wundermoosen.com) have a marvellous little utility called
Calendar X which calculates everything in all the calendars including
the Mayan one, using Mayan glyphs too. I suppose that the world
should have a big party on 21 December 2012 when the current Great
Circle ticks over to the next one....
--
Michael Everson * * Everson Typography * * http://www.evertype.com