Great I/O ports for FreeBSD based microcomputers?

[PacketMan]

I have an interest in tinkering with some I/O type projects with Beagleboard running FreeBSD. Can anyone suggest ports that would fit in quite well here? One of my boys is wanting a Raspberry PI, and while I'll let him do what he wants to do with it, I'm thinking some cross pollination between us might be fun too.

Thanks in advance.