A friend of mine noticed that Flickr videos were not playing on his new iPhone 3GS. Apparently, Flickr is dealing with a compatibility problem they have with the new iPhone OS 3.0 and have turned off video support for the iPhone until they sort it out. More details are here.
I tried uploading video from the iPhone 3GS to Vimeo, a popular alternative to YouTube for sharing video online. This can be done by emailing the video to a special account that Vimeo creates for you but, at least as of last week, audio wasn’t working. The video, however, did look better than it did on YouTube. I’m told a fix is in the works.