I am determined to celebrate this day in some way, although I am not sure how, yet. Oscar Wilde is one of my biggest inspirations in writing.
I suggest using this day to read something written by Wilde. Whether it be his only novel The Picture of Dorian Gray; one of his many plays, such as The Importance of Being Earnest; one of his short stories, such as Lord Arthur Savile's Crime; or one of his many poems or essays.
All his work is available online. You can read a good selection of his work here or, if you have an ereader, you can download any number of his stories, plays, etc. here. I, personally, have the great tome The Complete Works of Oscar Wilde which is 1200+ pages. Perhaps I'll pick up where I left off.