Unlicensed Mobile Access lets a dual-mode handset maintain a voice call when roaming between a GSM cellular network and an unlicensed wireless network like a Wi-Fi hot spot. AT handing a session over without disruption is quite another. Ongoing costs are more significant and harder to compare. Rebates and volume discounts are often apple iphones available with both technologies. For those few devices without embedded Wi-Fi, adapters are readily available for under $50. On the other hand, 3G is better for those who must stay online while traversing the great outdoors. Nonetheless, Wi-Fi is still best for those users who don’t need to leave the building or a designated coverage area while accessing the Internet.