I assume you wrote NeatReceipts in .NET. If so, you should have a look at mono-project.com. It may solve all your Mac porting issues--and might make a port quicker to produce than you anticipated. One approach you might take on the hardware side is to release an interim build that would support some scanner such as a TravelPro 600 (that already has a Mac TWAIN driver). That way, those of us who are trying to document platform diversity in the wake of Vista would be able to help you test your product.
Just for your information, I am an academic chief technologist at a major University. We. are seeing trends upwards of 50% attrition away from Microsoft this year. Our student, before, have been encouraged to get a Windows platform. This year, we've officially blessed full support on the Mac platform, and over half the new purchases are Macs. We're seeing the same thing in industry as well.
