I've noticed I'm within comfortable wifi range of a nearby coffee shop's open connection. I have an OpenWRT router that I'm not using, and thought it might be handy to have this connected to my home network (either via ethernet or wifi - I have a spare USB wifi card too) AND via the open wifi simultaneously. For example I could set it downloading files when my ip has reached filehost IP limits.
How would I go about this? I've messed around a little with /etc/network/interfaces & could probably follow a tutorial for doing this, but it seems it not a use case that's widely discussed. (Or I just lack the vocabulary to google it successfully...)