Are you a WhatsApp user who is currently running the beta release from the BlackBerry Beta Zone? If so, you might want to check the app to see if you have some new calling features enabled. Several WhatsApp users in the CrackBerry Forums have now reported the feature, which allows you to call other WhatsApp users through the app using data services, has now appeared randomly and have been testing it out.
Sadly, it's not showing up for everyone as of yet but there are a few ways you might be able to force it to appear if you simply cannot wait. If you know someone who has the feature enabled on their account, they can call you, and it will force it to appear for you as well, but that doesn't work in all cases thus far.
The calling features are something that have been rumored for months now and have also started appearing within the Android app most recently. WhatsApp, earlier this month confirmed to Mashable it was indeed testing the feature with a "small group" of Android users, but it would seem that testing has now moved onto BlackBerry 10 users.
Thanks, Jafrul and Usman!