I’m a big fan of freewayblogger’s work, and my office is a short walk from a highly-visible footbridge over Hwy 101 approaching SF — the math works out nicely. I spent an hour last night making a sign, and today a coworker and I took a lunchtime stroll and installed the sign. We used bungee cords to secure the sign, as recommended by FB. The whole thing took about two minutes. A bunch of cars passing below honked encouragingly at us.
I have no idea how long this sign will last (it may be gone already), but thousands of people surely saw it, at the very least. Definitely time well spent!