Ask for the Job!
The end of the interview is where you really have the oppurtunity to shine, and the best way is to wait for that employer to ask you "do you have any final questions for me?"
This is a great, great moment in the interview because you get to lean forward look them squarely in the eye give them a great smile and say may I have the job?
Best way in the world to end that interview they won't be expecting that question and many times many times I've had clients come back and say you know what, they said yes right there and then. So use that question and that moment to your advantage; it's the only time you'll get it.