Don't filter what you say with the consideration of whether or not someone might care. Instead, just say whatever you are thinking. Stream of consciousness is your friend. You are under no obligation to complete one thought before you start the next one. Nor, in the rare instances where you stop for breath and someone else takes this as an invitation to say something, should you imagine that what they say has any relevance or need to be responded to. Rather, just keep on talking about what you want to talk about, whether it take there words in to consideration or not.
Also, develop a deep interest in things which most people have a much more limited interest in. Good choices are Star Trek, Star Wars, Xena Warier Princes, your own pets, obscure political candidates, the most recent American Idol winner, etc. Find people who have absolutely no reason to be interested in whatever you've picked and start an innocent conversation with them that gradually leads to the topic of your interest. Ignore all social ques that you've reached the limit of their of their interest in the topic. Regard terms like "I've never really watched that show," or "I'm not into politics," or "I prefer classical music," as invitations to be converted rather then indications that they might be legitimately disinterested. When they progress to saying things like "Every time I've seen that show it's looked really dull," or "I really find nothing appealing about his voice," to be evidence that they're starting to come around and want to hear more.
If they start to leave, follow. Members of the opposite sex might try to avoid you with a trip to a bathroom. Don't fall for this. You can follow them all the way to the door and politely wait while they use the facilities. Then, when they leave the bathroom, pick up right where you left off. If they say that they have to study, do yard work, or cook dinner, this is clearly an invitation. What chore would not be made all the more pleasant by your incessant talking? Even if they ask you directly to please leave, you can deflect by saying "yeah, I really should get going, but you know..." and then picking up right where you left off.
Remember: There is no one more interesting then you, and nothing anyone else says is relevant to the conversation you are trying to have. Follow these simple rules and you're on your way to becoming a first glass bore.