This paper presents an architectural model for wireless peer-to-peer (WP2P) file sharing system for ubiquitous mobile devices. File sharing is one of the rationales for computer networks with increasing demand for file sharing applications and technologies in small and large enterprise networks and on the Internet. With the popularity of mobile phones in day-to-day activities, P2P file sharing in mobile phones is highly desirable, especially in 2/2.5 G mobile networks. The proposed model is based on a hybrid or semi centralized architecture with the central database server acting as an interface between the mobile devices. The P2P communication model employs the short messaging service (SMS) and multimedia messaging service (MMS) as the messaging medium. The mobile phone initiates a search for a particular file on the mobile P2P network using a general packet radio service (GPRS) connection. The database replies the ldquosearcherrdquo mobile phone with a list of all the available files and the details of the mobile phones that have them. Using this information, the requesting mobile phone makes a SMS connection to any of the phones provided by the database server. The mobile phone with the file then sends it to the requesting mobile phone using the MMS. We present an architectural model using mobile proxy, SMS and MMS, for a mobile P2P network for 2/2.5 G networks despite operator constraints.