Why can't we have different National Guard or Reserve units from different parts of the country rotate and do a week's duty each year assisting the Border Patrol and monitoring the fence. They can do training exercises part of the day, and assist with surveillance at night.
I don't know the viability of it, but I've had similar ideas that seem reasonable on the surface. It would give excellent training opportunities to the national guard.
On the heels of the success of the Minuteman Project, if I were a state legislator I'd be thinking about a similar project funded by the state. I don't know what it would cost or if it could possibly be cost effective, but I'd be looking into it. Ultimately, it may be up to the states to take the lead on this and allow border patrol to supplement state forces.