Friday was to be something of a special occasion in Northwest Arkansas, until extreme winter weather forced a change of plans. Word arrived yesterday that Treasury Secretary Tim Geithner would not be visiting the area as originally planned, but the visit was postponed rather than cancelled, and he would be rescheduling the visit. Originally, he was scheduled to meet with regional business leaders to discuss how government and the private sector can work together to out-innovate the competition and grow the economy, according to a Treasury press release. The agenda included a private round-table meeting with a group of undisclosed business leaders at the Arkansas World Trade Center followed by a visit to the manufacturing plant and labs of NanoMech, a small business that uses nanotechnology to manufacture products with broad applications, including machining and manufacturing, lubrication and energy, and biomedical implant coatings.