I'm with Pam. I don't think they made cleat covers for SPDs. I have some covers for my Keos. I can't say that I use them all that often though. I'd bring them along for a breakfast or dinner ride though. For minor amounts of walking, I try to put the weight in my heels.
Live with intention. Walk to the edge. Listen hard. Practice wellness. Play with abandon. Laugh. Choose with no regret. Continue to learn. Appreciate your friends. Do what you love. Live as if this is all there is.
--Mary Anne Radmacher