It's pretty fitting for this blog that there is actually a website out there called Wonderopolis! (Thanks Jasmin for sharing!) Each day, they post a new "wonder", which is just a fun fact or "wonder" of the day. The topics cover a wide variety of things, from "what is an aglet?" to "how much rain can a rain cloud hold?". The daily wonders could spark classroom discussion, a writing prompt, fit into your science/social studies unit.. the possibilities are endless! You can also view past wonders or search for topics if you are looking for something in particular.
Draw a Stickman is another fun website that would be a fun story starter or introduction to digital storytelling. It is an interactive adventure that reminds me of one of my favorite children's books, Harold and the Purple Crayon. You start by drawing a stick man, and then follow him through an adventure that you add things to the picture as it unfolds. Would definitely make a great SmartBoard activity! It could serve as a writing prompt also - stop the story at any point and ask the students where they would take it from there, or how would they problem solve the situation?