Anyone not on Verizon hurting for native VoIP on BlackBerry will want to check out this leaked beta of Skype Mobile. This is probably the closed beta that started about a year ago, and eventually graduated to full-time status. Carrier deals will probably prevent you from using this anywhere, but there’s always IM+ if you’re really hurting for Skype functions.
I’ve downloaded the app and tried it myself, and it doesn’t seem to play nice with my connection, and is designed more for basic Java feature phones with soft keys than BlackBerry. Launching the Help section crashes the app on the 9300, so I’m really not expecting much. You’re welcome to try your luck, though – grab the necessary files from Megaupload, load them onto your BlackBerry’s microSD card, and open to the .JAD through the Files app.