I want to pay with my cell phone.  I hope this integration trial with Cingular (http://news.com.com/Cingular+turns+cell+phones+into+wallets+in+N.Y.+trial/2100-1039_3-6143975.html?tag=html.alert & http://www.phonescoop.com/news/item.php?n=1999)  and credit card companies succeeds!  This is not the first I have heard of this there are even small grocery stores trying this (http://www.washingtonpost.com/wp-dyn/content/article/2006/09/24/AR2006092400789.html). 

I think this is incredibly convenient.  Microsoft is perfectly positioned for this.  They have a Point of Sale System (http://blogs.msdn.com/mikehall/archive/2006/11/01/channel9-the-difference-between-windows-ce-windows-xp-embedded-and-windows-mobile.aspx) and obviously strong in cell phones.  Microsoft if you are listening I want an API for this.  I do not want to manage the transaction, MS, credit card vendors and the cellular providers can work that out.  But I want to know about the transaction internally for applications I am developing.