New feature added on QRifier.com
Simply enter venue ID (get it from http://foursquare.com/venue/XXXXXX <- this is ID) and click Generate.
Print and attach to the entrance of the venue and people will be able to do fast check-in using favorite QR code reader.
iPhone/iPad/iPod and Android Foursquare app handlers supported.
for full-page printable image
iCal calendar events support added to qrifier.com