I have been storing packing material from some large purchases because I just couldn't bear to put it in the trash and end up in a landfill. Additionally after a year of living on Shellpot creek I am hyper-sensitive to Styrofoam in trash since every rain brings a new piece to be plucked from the stream. Thus I have been trying to recycle the Styrofoam packing peanuts and packing stuff that comes in with shipments.

In northern Delaware a company called Flo-Pac (actually
FP International) collects Styrofoam and
recycles it into more packing material. Their collection site is hidden away in an industrial park off of Ruthar Drive off of Harmony Road in Newark.
From North Wilmington it is a pain to get to and the trip should be avoided during afternoon rush hour. Take I-95 south toward Newark. Get off at the Rt273 exit going toward Newark. Go towards Rt 4 on Harmony Road from the Rt273 exit on I-95. Brave the reactionary traffic calming measures, go past Rt4 and make a left onto Ruthar drive. Make the first left into an industrial park onto Alan Drive, there is no sign. Go all the way to the end, past tons of Flo-Pac trucks.

The address is
111 Alan Drive (map). On the left is a door that looks like it goes into a factory, but is labeled pretty clearly, inside you can deposit Styrofoam for recycling into some bins.
I found out that they will take boxes full of peanuts or bags and loose form fitted polystyrene foam. It is clean polystyrene or Styrofoam only (
specs here), no cellulose peanuts, no polyurethane foam. Other
FP Locations can be found here.

Many years ago (13!) when I was a graduate student at the University of Delaware I organized our group of students to recycle the polystyrene packing material that we collected in the Chemical Engineering department. It was a pain because a little packing material takes up a huge amount of space. We finally told everyone where the place was and sent them off on their own. Only recently did I have enough packing stuff to return to the recycler for myself. I try to keep it to less than a trip every 6 months.
I am not sure that I was carbon neutral in my 40 minute round trip to recycle, but hopefully I won't see that Styrofoam floating down the creek someday.