Keeping notes is the best tip! I do this in my classes all the time because I learn so much more that way. It's like early preparation when its time for exams.
Another way you can keep awake is to sit close to the leader or speaker of the meeting. That means you should sit towards the front, not the back. When you are closer to the person that's speaking, it's so much harder to ignore them and start thinking about other things. They are also more likely to make eye contact with you and that will force you to pay attention to them!
A tip I have for women who have to attend many boring meetings is to wear mascara! Mascara will actually open up your eyes. So even if you loose track and wander off into a thought for a minute or two, it will still look like you are listening!