M.L.
Look at this as part of your son's job description. I have a wonderful picture of one of my granddaughters at that age, sitting in a beautiful field of Texas bluebonnets, and crying to beat the band because her mama was mean enough to SET HER DOWN!
So hang in there. It won't last. However, don't act over-concerned! When you do have to separate from him, maintain a sense of humor and matter-of-factness about it. (With one of my children, I found that playing "peek-a-boo" helped when I was in the kitchen and needed both hands.) Although he has natural one-year-old velcro tendencies, he's still watching Mama for cues to behavior. Pretty soon your modeling will win - along with some other factors - and he'll detach himself from you a little more.