Talk to people first. Put a sign up on the table asking for games of any level. People are often shy about approaching anybody in public and an open offer will give them a reason to approach.
Where to play OTB?

So your saying I need a sign lol.
I am saying you need to give people a reason to sit down and play. It may seem obvious to you with a chess board there and all, but many people don't want to look foolish by asking.

Yeah Phylar, going to probably just do that. However, I wanted to see if we could get some funnier suggestions, clever puns, or something witty.

A still remaining problem might be that many people who see the guy who set up the board and asking to be played via a sign will think: "This guy will be too strong for me."
And this most likely will be true for your average person. Many people who say they can play chess mean they know how to move the pieces and what checkmate is.
I've played like 3 or 4 this year. Was even a bit afraid that they might beat me despite me having joined a club.
Well, none of them came even close to doing that. I think they performed between 500 and 800 level.
So while your 1100 is low compared to other people playing on this site, for the average Joe it still means you're virtually unbeatable. ^^

A still remaining problem might be that many people who see the guy who set up the board and asking to be played via a sign will think: "This guy will be too strong for me."
And this most likely will be true for your average person. Many people who say they can play chess mean they know how to move the pieces and what checkmate is.
I've played like 3 or 4 this year. Was even a bit afraid that they might beat me despite me having joined a club.
Well, none of them came even close to doing that. I think they performed between 500 and 800 level.
So while your 1100 is low compared to other people playing on this site, for the average Joe it still means you're virtually unbeatable. ^^
Pssh, the one stranger I've faced out of the blue beat me hands down and went on to almost win against my mentor (at the time), an expert level player. Heh..

Also, ask at either your local library, or Chamber of Commerce, if there are any chess clubs nearby.
Or else simply Google your state chess association. They probably have all the chess clubs in the state listed on their website.

OK I make sign.
Let's have some fun with this... what should my sign say :D?
Will Mate for Food!

Pssh, the one stranger I've faced out of the blue beat me hands down and went on to almost win against my mentor (at the time), an expert level player. Heh..
The ones that play you despite you being the one who set up the board are of course those who think they are actually good. (which most likely happens in the case that they are actually good)
@varelse1: If he get's extremely lucky this will get him even something better than a game of chess. :D

Do you have any parks in your local town? Chess players like to hang out in parks. Set up a chess board in your park and so what happens. Also why not start your own chess club? This is what we did in Midwood in Brooklyn. We were playing chess in the park but it was either too hot or too cold or raining. So one of us went to our local library and he talked to the librarian and asked permission to start a chess club. Permission granted! Now we are in chess heaven!
Been hanging out at a couple local bookstores. Set up my board and then read soemthing while I wait, but rarely people take me up on it.
Is there a sort of way to get OTB going on that isn't so formal as going to a club?
The calibre of opponents playing in informal settings can vary widly and you have to watch out for the sharks who will show up out of nowhere who will make a little $5 wager let you win a few games to get your hopes up then they'll raise the stakes and suddenly become unstoppable tactical monsters and fleece you clean.
Pretty self explanatory Topic title.
Been hanging out at a couple local bookstores. Set up my board and then read soemthing while I wait, but rarely people take me up on it.
Is there a sort of way to get OTB going on that isn't so formal as going to a club?