http://en.wikipedia.org/wiki/Walpurgis_Night

In Finland we are celebrating today. Hauskaa Vappua (Wappua)!

That looks awesome! Hauskaa Vappua!

Coincidentally, tomorrow is the Jewish festival of Lag BaOmer which is celebrated with...bonfires.

http://en.wikipedia.org/wiki/Lag_BaOmer

The Wikipedia entry doesn't mention the pagan source of this holiday but it is quite obvious.

Vappu-related, there is Finnish-language doodle today

http://www.google.fi/#q=vappu&ct=labourday10-hp&oi=ddle&fp=62ce0ecc59b41cb9

There is related, May Day Doodle thread posted too at
http://blogoscoped.com/forum/170399.html