equant:

Of course people will want to know about your solution. It's certainly applicable in a case like this since a lot of people are going to have a router.

Will it work well in this configuration? I don't know. I took a quick look at my router and it is supported by OpenWRT. Sweet. I have yet to figure out how to add a serial port, but there are a couple of jumper blocks that may serve that purpose. If so that would be fantastic: no soldering.

Still, there may be one hitch. A lot of these ports, particularly the user added ones, are probably going to lack hardware flow control. This may make the link a bit less reliable. But hopefully not.