Pictures can be posted using www.imageshack.us or www.photobucket.com, but it requires an account. If you need to post a video sequence then perhaps rapidshare.de is a good choice. All you need to do is upload, press ok, and scroll down to get the link, which you can copy+paste into a forum post here. If you want you can bother about remembering the delete link too, otherwise it auto-deletes the file after it's been uploaded for long enough.