Can I use any of the iPAQ Pocket PC h5500 models as a phone?
No, the iPAQ Pocket PC h5500 models have integrated wireless LAN technology, which requires an 802.11b infrastructure in place for connectivity. Therefore this device is intended for data use, as opposed to voice phone communications. The exception to this would be the use of a separately purchased Voice Over IP software application, which will allow you to use this device as a VOIP phone in an 802.11b WLAN environment.