Skype is such a wonderful tool! In the classroom, this could be an amazing outlet to connect with other areas of the country and/or world. A great idea for the classroom could be to have pen pals with another school (possible one of my past schools) and then skype to talk about a math or science concept, and how their environment has changed the way they view a certain concept. For example, when learning about the four seasons, it would be fun to talk to my old school in Virginia about how different fall and winter are, and then we could discuss the way Virginia and Texas's geographical location have an impact on their seasons.
Wallwisher is also super fun! I created a Wallwisher for rounding through the millions. This could be a fun, quick assessment for teachers to use with students who have access to a computer, if the teacher decides to use the site for homework. Regardless, this could be a fun way to assess within the classroom. I love how you are able to see one another's posts and thinking! Here is the link to my Wallwisher: http://wallwisher.com/wall/roundingmillions