After much back and forth, the IRS has asked that Congress issue guidance clarifying that there will not be tax consequences from the personal use of work-related devices such as cell phones.
Document Excerpt
Although some of the proposed changes would add clarity, the current law will inevitably leave widespread confusion among employees and businesses. Therefore, Secretary Geithner and I ask that Congress act to make clear that there will be no tax consequence to employers or employees for personal use of work-related devices such as cell phones provided by employers. The passage of time, advances in technology, and the nature of communication in the modern workplace have rendered this law obsolete.
Link http://www.irs.gov/newsroom/article/0,,id=209795,00.html