Apple's having some issues with iMessage, again — for the second time in the last week, users are experiencing difficulties sending and receiving messages on both iOS devices and Macs running OS X. Symptoms appear very similar to the last outage, with messages hanging and failing (or being pushed through as text messages, on iOS). A number of staff members in Boston, New York City, San Francisco, and other locations have all experienced this problem, and a quick Twitter search shows that many other users are having similar problems. Furthermore, Apple's own iCloud status site indicates that iMessage is not functioning for "some" users. We're reaching out to Apple to see if it has any information on the issue — in the meantime, let us know if iMessage is working for you in the comments.
Update: As of about 6:15pm ET, things are slowly returning to normal. We've successfully send and received messages from a number of different phones and Macs in different locations. While things aren't back to 100 percent, functionality does seem to be returning pretty quickly.
Update #2: According to both our own testing and Apple's iCloud status page, iMessage is back up and running.