There comes a time in every Android user's life where you want to install an app not found in the Android Market. If it's your first time, you're greeted with, "For security, your phone is set to block installation of applications not obtained from the Android Market" message as you try to install. But how do we get there?
To allow app installs from non-Market apps, tap the menu button on your home screen, then choose Settings >> Applications >> Unknown sources.
Who are these "Unknown sources," and what do they want? Simply put, it's anything other than the Android Market. Could be an app sent by e-mail. Or downloaded from a website.
If you're worried about the security implications of allowing unknown sources, there's an easy fix -- install the app from outside the Android Market, and then hit the checkbox again to turn them back off.
If you're on an AT&T phone, you won't have this option, but Android Central's got you covered. Head on over to our very own Sideload Wonder Machine
on the forums to get your non-Market install on.