Wireless networking is becoming an increasingly important communication means. Entry points to content delivery networks (e.g. portals) have to cope with the primary necessity of distributing multimedia contents to 3G mobile devices. In this paper we discuss the software architecture of a wireless Internet application we have designed and implemented to support the distribution of Mp3-based songs to 3G UMTS devices. Alongside the operational description of the proposed architecture, efforts have been made to examine the effects that Internet traffic has on the performance of UMTS networks, due to the distribution of Mp3 files by means of our wireless application. The download time measurements we have experimentally obtained show that combining modern 3G mobile network technologies with an appropriate structuring of the wireless Internet application may be very effective for the fast distribution of pre-recorded music to mobile clients.