I protest on the principle that I bite my tongue every time I see a commercial chain category, but I'll tell you this, if you can make it clear what we're waymarking and describe it in a way that makes me understand what is interesting and unique about these sites, I'll vote for it. I'd recommend establishing a special criteria. At least 100 years old? That'll happily throw out BOA with their branches on every corner. Do they have to be in service as banks or will former banks (of historical significance) be allowed? How do we post banks that have changed names several times over the years... as the first name or the current name? How do you want the long description written? What are you thinking about for variables?
Tell me more. :)