Any experience buying and renting a billboard on a busy road?

[Malcolm Lawson]

Instead of purchasing another rental home, I have been thinking allot about purchasing land on a busy road and building billboard and renting out space.  I am a real estate agent so Ideally, I could build or purchase one with 4 smaller signs (two facing each way) and I could use one to promote my real estate business and rent out the other three.

Does anyone have any experience with this and could point me in the right directions?  I am guessing I would need to get it approved by someone in my county or city before building, who would I talk to about this?

I have also heard if you own a commercial building you can hang a large advertisement on the side of the building.  For me, I would want to hang a large banner promoting my business and even If I just broke even on a small commercial building it would be worth it for free advertisement.  Anyone experience with this?