Citizens of the EU, the US, Canada, Japan and Australia are given a free stamp on arrival. Most other nationalities must produce a valid "Iraq - Kurdistan Region" visa on arrival. However, you will have to report to the Residency Office within 10 days of your arrival. This involves many forms to fill out, around $30 USD in fees as well as a compulsory blood test to check for Hep C and HIV. Be prepared to wait for around 2-3 hours throughout this whole process.
Border control is fairly strict understandably. If you have a contact in Kurdistan, come armed with their name and address. If you don't, make sure you have a very good idea of what exactly you will be doing and where you will be staying. You are also more likely to get in if travelling with someone else, and if you are well-dressed.
The KRG Kurdistan Regional Government has produced a fact sheet PDF on travel to the Kurdistan region of Iraq. (http://krg.org/uploads/do...)
