For those looking for a way to use their Windows Phones as virtual walkie-talkies, you may want to keep an eye on Talk2Me, a new app from NTWorld. The app allows you to record 15 second voice clips which you can then send to your friends and family. They receive the message and that's that, no typing involved. The app comes in two versions: paid ($0.99) and free (ads), but when we bought the app we noticed our ad bar did not disappear. Perhaps just a bug on our end, but be warned.
The app does have a few downsides: you can't lookup anyone via phone number or email just yet, though the developers seem keen on adding that ability in the future. Also, this is a Windows Phone-only system, meaning your friends on Android or iOS won't be participating. Having said that, it did work when sending and receiving voice clips with no issues. Toast notifications alert you to a new message in addition to the Live Tile counter.
The graphics and UI could use some work being very basic and blocky, but if you're in it just for the voice-messages, this is really your only choice at the moment. We do know that TalkBox should be out soon and even Palringo should make a return, so keep that mind.