NHS West Sussex are using QR Barcodes to embed messages on their Facebook presence. Like many other NHS areas (the UK's National Health Service) West Sussex use a profile as their presence, rather than a page or a group.
The screen shot below, taken on 16 November 2010, shows a QR Barcode posted on behalf of the Health Visitor.
If your phone has a QR reader (there is a free app for the iPhone, and probably for lots of others).
If you do not have a reader handy, the barcode reveals "There were 130,000 babies born in London last year."
At this stage this example is more a concept than a finished approach, but an interesting indicator of how things might go.