Open your data! That's the theme behind the new Semantic Web logo created by the W3C. The three sides of the tri-color cube are meant to represent the RDF triple model, and the peeled back lid is suggestive of the main theme of opening your data for everyone to access. For now they ask that you use the images that include the W3C logo, at least until the new Semantic Web logo becomes more widely recognized on its own.
They've also created 80x15 sized buttons for RDF, OWL, SPARQL, and GRDDL! I'm not too wild about those kinds of buttons, but I'm sure we'll see them springing up everywhere in no time. The buttons come in blue, green, orange, gray, and purple.