Cool website alert! At
Meetways.com you can find a "point of interest" (such as a coffee shop or restaurant) at the exact halfway point between two addresses.
So, for example, if
Diane and I wanted to get together for coffee halfway between her church in Minnesota and my clinic here in Longview, WA, Meetways tells me we could meet in Harlowton, Montana. I think the Cornerstone will fit the bill. Look at these friendly people waiting to serve us!

If
Presbygal and I decide we want to have lunch, it looks like we could meet at the Honey Lake Campground Restaurant and General Store near Milford, California. I googled a picture from Honey Lake. Hmm... hope this isn't the place, because it does not look promising.

Back to the drawing board...