In all the time I have been on this forum I haven't seen the magic of 3D printing mentioned, so I will kick things off.
For Netduino based projects there is nothing cooler or cheaper to make it look professional and protect the circuits than a custom 3D printed case. Not only is it cheap to create just one, but you can draw it on your computer and get a quote before you spend a penny.
Step 1) Find a free 3D drawing program like Sketchup that is right for your project by Googling "3D modeling software". If you don't want to learn 3D drawing then you can hire a designer. I could design small projects here.
Step 2) Find a quality printer to hire. You can Google that, or I can do it for you. I have the top-of-the line Form1 SLA printer that I use for awesome Netduino cases listed right here with a review. I currently print at cost since I already own the printer for my own use.
Step 3) Upload your 3D file and your parts will be shipped to you just like anything else ordered online.
I would love to help you guys discover the potential of 3D printing, no matter if you use mine or Google others.