The allure of Snapchat is that all pictures and videos sent through the app vanish a few seconds after being sent. They're completely obliterated not only from the phone, but from the Snapchat server, as well. The popularity of the application has even incited Facebook to release its own real-time picture and video messaging application, aptly titled Poke.
One of the biggest criticisms (besides the wave of recent security issues) of Snapchat is that even though the messages self destruct and it alerts the sender when their recipient takes a screenshot of the photo that was sent, it doesn't actually disable the ability to do so. While photos are able to be saved on both Snapchat and Poke (only via screenshots), there is no way to save any of the videos that are received.
Actually, I lied. There is.
It turns out you can easily access all of the videos sent to you from your computer with any iPhone file browser—as long as you don't open and watch the videos first.
To save the videos, all you have to do is connect your iPhone to a computer and open up an iPhone file browser such as iFunBox. Once your device shows up, double-click on User Applications and find Snapchat. Double-click on it.
This should bring you to several folders. Open the folder titled tmp.
Inside this folder will be all of the videos you've been sent, but haven't watched yet. Just drag them onto your computer's desktop or into a folder to save them.
The same procedure can be followed to snag a video off of Poke.
A spokesperson for Facebook issued a statement on this issue, saying,
"People could also take a photo of a photo you sent them, or a video of a video, with another camera. Because of this, people should think about what they are sending and share responsibly."
In other words, even if a company tells you it's totally safe and your privacy is protected, be careful what you send because you never know when it can come back and bite you in the butt (and they're not responsible).