If an agency accepts email submissions of pictures is it still better to send in hard copies? Would it increase the chance of catching their attention?

I believe hard copies are always better than CDs or digital copies sent via email. Hard copies can easily be passed around among bookers and agents for a quick evaluation. Web submissions will likely be viewed by one person. If that person wants a second opinion, he/she has to bring someone over to the computer to view the image. In a busy agency, bookers are constantly on the phone and it's much easier to bring over a picture for a quick glance followed by a thumbs up or thumbs down. Additionally, you can control the quality of a print. You cannot control the quality of their monitor.