Pagan Blog Project? Basically, it's a blogging your way through the alphabet one week at a time. Each week has a letter assigned to it, and every Friday you write about a topic starting with that letter.
For example, tomorrow is the first week, so the letter is A. You could write about altars, Ahrodite, air, arrows, apples, ancestors, and so on. Each letter gets two weeks, so the second week is also A, so you'd pick another 'A' topic. Then the third week would be B, and so on. (Some just do one post per letter, every other week.) It's also possible to join in part way through should you come to this project late, just start up with the letter of that week. The posting schedule can be found here.
More information about the project can be found here.