a) you have too much time on your hands.... get a hobby.
My wife says I have too many now

b) you have too much storage space available for seldom used items..... share some of it with me.
Not really, I am running out of room in the garage.
c) you have too much HDPE laying around.... you should send me some. (enough for a short router table fence)
It is kind of heavy you know, but I might be able to be convinced, we'll see what is left after I make the dogs a new feeding stand.
I save even the small scraps of that stuff, it is so expensive.
The stuff I am using now is what is left from a 3/4" x 54" x 96" sheet that I bought when I was running scuba charters and needed "stuff" for the boat.
What a hassle handling that was, has to weigh well over 100 pounds and the edges are razor sharp.
This stuff isn't the same that you get at the woodworking shows, it is not smooth, rather it has a very small pebble grain. But it is slick, and would probably work good for a fence.
d) Can you adopt me? (well, actually, my two daughters, that's what I need the storage space for anyway...) 
Join the crowd - My daughter got engaged, moved out and left all her stuff! And she moved to England, so it is not like I can go drop it off on her doorstep

But, she is coming home for Christmas and I will tell her about my plans - Her and child #2 with the basement storage are being put on notice: I am on year 1 of my 10 year plan - in 10 the basement will be empty of all junk (except mine) and we are leaving for warmer climates.