As trentm in the forums posted, Tumblr has rolled out their own official BlackBerry application. Personally, I'm a Posterous fan myself but if you frequent using Tumblr you'll want to check the app out for sure. From what I can tell, all native Tumblr functions are in place within the app. For example text, audio and even video show as being supported features and this is only the first version. Give it shot if you are a Tumblr user and let us know how it works out for ya.