Keeping code clean - Decorators for Error Handling?

I read a review a few days ago of the new book by Robert C Martin (Uncle Bob) 'Clean Code'. I'm going to order a copy as soon as I clear a couple of books from my current reading list backlog as it sounds interesting and the Uncle Bob blog on Object Mentor is one that I always enjoy to read. One of the things that stuck in my mind from the review was that the 'Do one thing' principle applies even