Interested in learning everything there is to learn about Wi-Fi-enabled phones? Here's the complete scoop. If you want the down and dirty details for some quick decision making, here they are.

1. More than one type of Wi-Fi phone technology is out there. Many have just one radio (the Wi-Fi) for connecting wirelessly to a voice-over-Internet Protocol (VoIP) service. These are for calls made on-site in offices, etc. Others have both cellular and Wi-Fi radios on board and can transition from wireless VoIP networks to cellular networks. Know what type of calls you'll be making most often before choosing one over the other.

2. While Skype and Vonage both provide good VoIP services for home/consumer use, they aren't truly enterprise class. Enterprise customers should speak with their telecom providers to determine the best VoIP and Wi-Fi-wireless calling options.

3. You can't necessarily just hop onto any Wi-Fi network to make calls. At a Starbucks and want to buzz your significant other? Too bad. Any sort of protected network that requires a log-in typically blocks calls, even if the network itself is free to use.

4. Roaming from Wi-Fi to cellular networks (referred to as fixed mobile convergence, or FMC) requires special phones, special plans, and is currently only available from T-Mobile in Washington state. While trials are under way around the world, none of the other U.S. carriers are discussing their FMC plans.

5. The technology isn't quite there. Battery life on Wi-Fi phones is poor (one day of stand-by, several hours of talk time), even mediocre security gets in the way, no E911 services are supported (though Vonage has it's own emergency response system), and the phones are expensive, ranging from $180 to $350 for Wi-Fi-only models.