VoWiFi phones are a dime a dozen lately, and you can probably purchase one for as cheap as an ordinary cordless phone. But if you already have a personal digital assistant (PDA) that supports WiFi, then you can probably use your existing gadgetry to place and receive Voice-over-Internet Protocol calls through a Wireless network.
For instance, most mid-range and high-end HP iPaq Pocket PCs have built-in WiFi support (those that do not will take in Secure Digital I/O WiFi cards), and you can actually install mobile versions of popular software VoIP clients such as Skype and SJPhone. With some clients, you don’t even need to set up an account on your computer, since you can do it on the PocketPC itself.
What’s great is that you can also sign up for access to regular telephones, such as with SkypeOut and SkypeIn, and you can use your PDA to call and receive calls from landlines and cellular phones. Your PocketPC can even have its own telephone number!
A while back, I installed mobile versions of Skype and SJPhone (a SIP-type VoIP client) on my iPaq and used it on our office network. Calls were crisp and clear—it’s as if I were using a mobile phone.