Ash Wednesday involves marking a cross of ash on the forehead, in rememberance of our mortality. Sometimes the ash is made with the burnt remains of the palm fronds from last year's Palm Sunday.
Don't forget to check out Where the Map Ends. Since we're all about books here, take a look-see at the books page, which has an extensive list of Christian (presumably mostly Protestant) sf/fantasy authors and their work.
Proudly bringing more Protestants to Mass than any other holiday since 1962.