If you can get a tax equivalent yield of about 3-4%, it might be good to get in on Munis. I've been looking into doing the same. Which State are you in and what are you currently looking at?
As you know, high yield savings accounts are now returning less than 1%. So there is not much out there that is safe and giving some kind of return. I have some cash sitting in pool bonds that return a fixed 5% but those have higher risk that munis.