Why Blog? What I'm thinking

The conversation that I had with my Yr 7 students made me think about why I have been asking them to blog.
I think one of the things that I could do would be to provide them with some really powerful opportunities to see the way the web can make a difference to people in the world.
An example would be to show them Sarah McLaughlin's website and how she has created a video that simply shows what can be done with the $150,000 that would be normally be spent on making a video release for a new song.
Another would be to use the images that I came across on the reuters website which has a series of topical photo stories and images that you could use and maybe add a song to it to get more effect.
How powerful are images??? and the messages they can send. Can I help the students see this relationship and the power of being able to reach the world even though they are students who live in a small country town in the middle of Victoria.