I read Simon Monk's excellent new book on designing PCB boards with Eagle earlier this week. It turns out that PCB design is actually much easier than I realized, at least for the simple boards that I am interested in.
My first board design contains no active components and is simply a way to cut down on the number of interconnecting wires in G-Force and to remove the need to use a breadboard to connect the 5V and GND connections between all of the sensors. Here's a render of the board from OSH Park. The total cost to make the board was only $15 for 3 copies, including shipping.