Update: It seems RIM has pulled BeepUs from App World for the time being. No word on whether it was an issue with the app itself (like a major bug) or if they just felt it was too similar to the voice note feature that's already included in BBM. We'll keep you updated when we know more.
What it does in a nutshell is make push-to-talk even easier with your BBM contacts. As a BBM-connected app it automatically adds people from BBM with that app onto BeepUs and allows you to start "Sessions" with them with the app. In a session, you can chat, PING, and send voice messages all in one seamless place. The cool thing about this app is the fact that you can add multiple and have multiple voice messages sent among participants. The best part of this app? It's free so while it still has a couple of bugs, be sure to give a test run!