Doorstepping people can work, however, you have to know who you are going for first. Just turning up and expecting to get names or access is just not going to happen.
There's no point in leaving a CV at a desk, you need to make sure it gets to the person required.
JASPA, I can pretty much guarantee that Paul will not appreciate you putting his e-mail address up on here. Not only will he now receive a flood of CV's, but also the spambots will have a field day.
How to win friends and influenece people...