This might be a stupid questions. but how come the you tube videos are not clear and i thought you were able to go to any website and stream video or music?
the browser needs to have flash support. otherwise you're looking at a mobile version of the site and any videos will obviously be lower quality / viewed through a your media player via a link. currently, I know of no browser on BB that has flash support.
On my windows mobile phone I used Skyfire. It was amazing. It literally would load and play any website. Again you'd have to be on Win Mo and its still in beta :P As a general rule, you cant use flash on mobile phones