It looks like AT&T is starting to loosen its crazy restrictions about the ability of its Android phones to download third-party apps which has generated a lot of negative feedback from its customers. In fact, AT&T Android users have been forced to root their phones or use the SWM to enable sideloading.
Good news people, AT&T has enabled sideloading on the newly announced Samsung Infuse 4G and you can now just go to your settings and check that “Unknown Sources” feature and you will be good to go. Unfortunately, not anyone on AT&T will be or is interested in getting the Infuse 4G which means that an update may be in the works for the rest of AT&T Android phones but we are not sure if this will cover the older Android devices.
via Android Central