Facebook has updated its Messenger app (which allows iOS and Android users to chat with the site's messenging service) with some interesting VoIP features. Users can now save and send voice messages between Facebook accounts, meaning that if you don't want to bother typing a long message out, you can record it as a voice message and send it around to your friends and family as needed. That functionality is in the latest version of the app, which has been updated and is available for free (with a Facebook account, of course) right now.
Facebook is also beta testing (only in Canada right now), a live voice-over-IP service, similar to Skype or the other VoIP options out there. That service isn't live in all stores yet, but eventually, Facebook users will be able to call each other over the Messenger app, meaning that you'll be able to not only contact any of your Facebook friends directly, but you can do so without using cell minutes, if you're still limited on those. That should be a fun feature -- there are already a few ways to do that (including the aforementioned Skype app), but having direct access to your Facebook friends list should be useful.
Facebook's really figuring out iOS lately -- after a relatively weak start with its own official app (which the company finally sent native later on last year), the company is starting to show that it understands just how important the iOS userbase is. It'll be interesting to see what Zuckerberg's social network does next.