Shrini Kulkarni has posted some interview tips. I've conducted a number of interviews over the last year and have been surprised at the obvous lack of effort interviewees have put into their preparation for the interview. If you highlight certain technologies as your key strengths and you're are interviewing for a senior developer position, I think you should be able to talk in some detail about the concepts underlying those technologies. I'm not interested in factual detail such as names of API functions, etc, but a general grasp of the technology which you should have acquired after using it for several years. If you've not used a particular technology for a while then spend a few hours before the interview reading up on it and bringing it back into conscious memory. To say that you not used it recently and can't remember anything about it doesn't exactly further your cause. Most of all I want to see some enthusiasm, why you think a technology is particularly cool, why you like using it, even what you don't like about it and how you would do it better, anything to show that you have thought more about it than how to use the Visual Studio wizard.
Drawing diagrams on a whiteboard is always a good thing to do. It gives you time to think and makes it much easier for the interviewer to understand what you are talking about, for example the architecture of a system you've worked on. If there is a whiteboard in the interview room, don't wait until you're asked to draw a diagram; if you think you can explain a point better this way, just ask the interviewer if its ok to do so.
It can be difficult for introverted developer types but you have to make some effort to sell yourself. Not in a pushy salesman way, but using opportunities to reveal your skills, experience, and opinions. If you don't it will be more like an interrogation and that won't help you either.
Maybe the reality is that most people working as developers are not very happy in their job and thats why displays of enthusiasm are fairly uncommon, but that doesn't excuse not being able to talk about your key skills.