It is exactly what our service QRpon is about. This service lets any business create a mobile site for publishing data in social networks in exchange for some confirmation (coupon, discount info etc.) The process of creating mobile site is simple. Just set some text information about your business/offering, set a text for publishing in the social network and text for the confirmation. QRpon service will create a mobile site as well as QR-code for it. You can test this site (process) using this QR-code. If everything is Ok, just print this QR-code and place it on your business site. This QR code presents a physical (on-site) checkin for the customers.
End user can scan QR-code right from his/her phone, open mobile web site andyou’re your info/offering. If user is agreed, he/she can login to social network (right from the mobile site, there is Facebook connect button). Site will automatically publish your data (see above) to user’s wall/time line and return back the confirmation screen. This screen (e.g. coupon) could be presented to the staff for getting benefits. In other words it is like QR-code for coupons – that is the where the name QRpon comes from.
You can treat this service as pay links in the physical words. Customer pays for benefits by placing business data in the own social graph. Customer will get the benefits; business will get the social networks marketing. And the process works without the intermediate broker (read- without the checkin/places services).
On the main page QRpon service you can see a test QR-code. You can scan it and see how does this process work. For the accepting you need to login with your Facebook ID.
And for your own action just click 'Create QRpon' link. Set service info(description), text for publishing and the confirmation. Mobile web site generated by the service works with any HTML5 browser, so you can use it from iPhone, Android, Samsung etc.
P.S. and here you can create customized Like buttons
P.P.S. and here you can a huge list of services and mashups with QR-codes: QR-code how to.