Max - I did use Eagle. I currently use the free version. It's limited to two layers and approximately 3" x 4" in board space. It's also limited to non-commercial use. It's a great low-cost way to start designing PCBs. If I ever start to sell any of my creations, I'll need to upgrade to a commercial licence.
Hi Duane -- what you didn't mention was that we first started bouncing the idea of this sensor board around one Friday afternoon -- when I talked to you the next day (Saturday afternoon) you'd already designed the board and sent a panel off to be fabricated -- you completely blew me away with this. Did you say you use Eagle PCB for these projects?