Spend the day on B3ta mocking, ignoring and upsetting the massive waste of public money and time that is two people you'll no doubt never meet or share anything in common with going through the motions of an over the top tradition.
Do what you want or don't, I'm easy either way.

Some suggestions:
Be as offensive and unpatriotic as you can so B3ta becomes the one stop shop for summing up the disgruntled nations outpourings.
Highjack the day by staging your own pet wedding, fuck knows the long and happy relationship between your rabbit and guinea pig is as important to me as the Royals.
Spend the day drinking and reply to every picture posted on the board with an update of how happy/sad/angry/happy/nauseous/asleep you are feeling.
Carry on on b3ta as usual.

This is not restricted to one board, post pictures on main, write a poem on Talk, upload your own stage production of the day on Links, etc

Add your suggestions below and I'll add them to the main list if I remember I've started this.

HappyToast Groat froth

You can have this: Couldnae Gie A Fuck

Fat Boab of dailyreckless.com fame