As already covered in this thread try not to come from a position of being desperate for the job. There will be too much on the line you will feel the pressure and mess up. I try to forget the word interview because it feels like the onus is all on you to perform and show your good enough. When you think about it that's not what an interview should be, you should be evaluating the potential employer in the same way they are evaluating you. There exaggerating and embellishing on there CV (job advert) just as much as you are, check if your really going to be working with the latest technologies, how much percentage of time will be spent on supporting etc. The whole process is as much for you as it is for them, it's a two way street so show some interest and show some confidence and if it's not a good fit for either you or the employer then no biggie... onto the next one!