Thanks for the laugh ToucanSam. I was trying to picture how you were sewing on your wall when I too realized what you were actually trying to say.
I have seen this before but didn't think it was necessary for me. I am re-thinking that since my DD's quilt will be queen size and I will need more workspace than I currently have.
JoAnn's and Hobby Lobby also carry the vinyl. JoAnn's has many thickness' available. Hobby Lobby had two or three I think last time I was there. Only Wal-mart's with fabric dept. still in store carry the roll vinyl which is normally found on a stand with several other rolls of vinyl tablecloths by the cutting table.
Otherwise, go to the Hardware dept. and go to the aisle where they sell the heaters, fans, plastic window coverings, and such. I think most of these will be too flimsy and don;t get heat near them as they are meant to shrink when placed on window and use a hair dryer to shrink to fit. Be sure you get the size package you need for your table. Remeber, "measure twice, cut once."