Taking a tax deduction for your new iPhone 3G (or other cell phone) and the monthly service bill that accompanies it may be a bit more complicated than you think, even if it is used primarily (or exclusively) for business purposes. It's complicated because cell phones are considered "listed property" by the Internal Revenue Service and have been since 1989. "Listed property" includes items obtained for use in a business but designated by the Internal Revenue Code as lending themselves easily to personal use. The designation of an item as listed property has implications for depreciation deductions taken by the business and the computation of net income if there is an ongoing expense linked to the listed property. In the case of your new iPhone 3G, you have the electronic device (or handset) and the monthly service bill (expense) that accompanies its use.