Here's a link:
http://shine.yahoo.com/financially-fit/5-costly-wedding-mistakes-142900760.html
I can get on board on some of these, but I don't agree with some.
1. I think the invitation conveys the formality of the occasion. No offense to anyone who sends invitations electronically, but I would think the wedding is pretty casual.
2. Cupcakes don't always save money.
3. I would rather the couple donate to a cause they like in private (if they want to go this route) and not associate it with a favor, because not everyone approves of the same charities and organizations. I wouldn't want money donated in my name to a cause I don't agree with.