vBulletin I don't use it. But others use it, and I visit their v-bulletin forums. Such as game forums.
My favorite online application is YouTube. We could find tutorials, entertainments and a lot other videos. You can find files or stuffs very easy on YouTube. Example: You want 'File X'. So you search it on Google or other search engines. They may give you none or tons of links. and among the links, some may contain virus or give you invalid links. While YouTube, there will be video to guide your steps, they will provide working links and if not, you still can comment on the video or PM the uploader to change the link. With video as guide, it will be much easier to understand then in words. Just like the SST Students blog activities. They use YouTube tutorials to teach us how to use Google Maps and more.