Automation is probably the best answer to the problem, the aforementioned fxcop or team system solutions work well.
There might be another issue at work here, I know when I was a junior dev I was handed a huge coding standards doc and asked to build everything to match that. I remember being overwhelmed with the sheer number of items, I plain couldn't remember to do it all, particularly when trying to get something working to a deadline..
If your standards are verbose it might be worth picking out the items you'd most like to see fixed and focus on those, then phase in the others gradually, it might work better than expecting them to change all their bad habits at once.
