I was just chatting with a colleague this afternoon about some difficulties that she has had trying to get elementary teachers onboard using Google SketchUp. It is such a great tool for introducing some practical application of geometry and it is so easy to learn yet so powerful once you become competent with it. I just introduced a grade 8 class to it the other day and all it really took was me showing them how to draw a rectangle using the rectangle tool, then how to pull it into 3D using the push/pull tool. The kids took it from there and with no additional instruction or other materials at all, they were building houses and furniture and all sorts of stuff in no time. Nevertheless, I can understand how some teachers may be intimidated by something new and different from anything they have worked with before.
When I taught in the elementary school, I introduced kids and teachers alike to working in 3D using the IKEA Home Planner. The software is free, it runs in a browser and only requires you to install a simple plugin. It allows you to create rooms to your own specifications and fill them with furniture, fixtures etc... from the IKEA catalogue. You can rotate the rooms around and see them from a top view as well. This was a wonderful tool for teaching perimeter and area and throwing in some discussion about money while I was at it. As a class, I would have the kids create one of the smaller rooms in the school. We would measure it accurately and work out where the electrical sockets and everything else were, then recreate it in the home planner. Then, I would task the kids with designing the room. We treated it as though each one was competing for an interior design contract so they would have to keep to a budget (the prices are all included) and various other requirements for how the room might be used. Later, the kids would go home and measure their own bedrooms and recreated those. They had a budget to redesign their own bedrooms. It was a fun way to introduce the math but it also got them used to working in 3D. Making the transition from there to SketchUp was a piece of cake and I got much less resistance from teachers as a result.