Not sure how excited to be about this, but I suppose, if invented usage celebrates any day, it should celebrate National Grammar Day.
It's certainly nice to see that the usage blog community is alive and well -- I found out via twitter about this grammar limerick contest.
I'm entertained enough that I will participate by pretending it's about cognitive grammar, and maybe grammatology, rather than the pedantic lack-of-error grammar and a celebration of cringes. I intend to have a grammartini, at the very least.
(Thanks to Maveric for the tip!)
Update: Unfortunately, his week is also National Procrastination Week, so grammar will have to wait.