I have always hoped that RIM would add Push to Talk or other voice calling features into BBM. So far RIM has just made it a little simpler to send voice notes but nothing near a full push to talk with presence solution. That has not stopped Tuk Digital Solutions from trying. I noticed a few friends on BBM were using BeepUs and decided to check it out. The free BeepUs app uses the new BBM social network APIs to allow you to have free Push to Talk conversations with your BBM friends.
I am not sure how well this will work continuously since RIM does have some limits on the transfer size and continuous connections on BBM but the concept is awesome. If you like sending voice notes or using Push to Talk you will love BeepUs . Hopefully Tuk keeps on adding new features to the app!