I've been using
Google SketchUp for the past two years in my 8th grade classroom. SketchUp is a free 3D software program that allows you to build models of most anything. It is very easy to use and the
Tutorials are excellent. In fact, most of my students use the video and self-paced tutorials to teach themselves how to create the models. There is a
Google 3D Warehouse where you can place your own models or upload someone else's. There are numerous ways to use SketchUp in the classroom to integrate different areas of the curriculum. Mathematically, students can use geometry as well as basic measurements when they are building structures. For history, students might create an ancient city. The Industrial Arts teacher at my school has her students create model cars using SketchUp before beginning the actual building process. One of my students built a model of a computer, and another student built an entire neighborhood! This is also a great way to involve visual learners. CLICK on the images to enlarge them!
Bubble.us is an awesome website. According to the site, the goal was to create a "simple to use and easy to learn tool to help people organize ideas in a way that makes sense to them." The cool part is that you can share your stuff with collaborators, save your projects online, change the colors and sizes of the bubbles, add/delete arrows, and move the buttons around on the page. This site was created in 2006 by two guys from Russia, Kirill and Levon. Educationally, teachers can have students use this site to organize their ideas or to visually depict concepts in reading and writing. Graphic organizers are a powerful way to communicate ideas visually. Here is a sample that I created using the site: 
