Folks this has been around for some time now. It's the best tool you can have for building your own projects. It's Google Sketchup. Download the free version and draw in CAD and figure out EXACTLY what your future project needs. It is a cinch to plot and draw, it makes it easy to figure out what materials you'll need. You can show your renderings to friends and share them online.
For example once you've downloaded the program click this link to see what my 400g tank will look like in my dining room in relation to my 125 in the spare bedroom. Don't be shy. Use the toolbars to rotate, flip, skew, remove guide lines etc... http://sketchup.google.com/3dwarehou...80e39ef98c05e1
I recently had a large sump made for my 400g project. Take a look at how close the drawing resembles the actual sump. http://sketchup.google.com/3dwarehou...80e39ef98c05e1
I made one change from a 2" bulkhead hole to a 7" hole for a filter sock. Finished product. http://i30.photobucket.com/albums/c3...s/DSC01291.jpg
The builder was able to charge $50 less as he had all the dimensions laid out for him and in a 3 dimensional model he could use to see what I wanted. It also only took him 3 days to get around to completing the project as it was much simpler for him as he did not have to draw or figure out what I wanted.