Part of our coding standards is the absolute prejudice against trailing whitespace.
I often run the following vim regex to look for such creatures:
Even better yet, add the following to your vimrc to show you where these pesky creatures live:
syntax match ToDo /\s\+$/
Note: I used ToDo out of personal taste. Some people might prefer to use Error. :)
PS. Related post: vim: How To Highlight Unwanted Spaces