J.P.
It sounds like separation anxiety. My first son got it around 10 months of age and it was a phase that lasted just a few months. I found this article that may help.
http://www.drgreene.com/21_1183.html
I also am more of an attachment parent and I just helped him cope better. I would explain that I was going somewhere and that I would be right back. When he started to cry I would keep talking to him as I walked down the hall etc. I also just let him come with me to the bathroom etc. It is a phase and if you cater to it that isn't a bad thing (your not spoiling him). He needs the reassurance that you will return. It is a very healthy phase that all children go through at differing degrees. You may also want to introduce an item for him to comfort himself, i.e. a lovey. My some is attached to an eoyre doll some kids like blankies etc. Good luck and I know it is tough but IT WILL go away.