U3P files are portable programs that are stored on a U3 Smart Drive. A U3 drive is a special type of USB flash drive. The U3P file will allow programs to be run from the flash drive on any Windows computer. If needed, the U3P may automatically install some files on the local computer. Common manufacturers of U3 drives include: SanDisk, Kingston, Verbatim, Intuix, and Memorex.