We're in the process of changing curtains. After removing all of the original and previous owner's curtains, we have many tiny holes. Looks like someone was practicing with a small machine gun. Not sure what others have done, but I found these nylon plugs on ebay. They're designed for 1/8 inch holes, pretty much the size we have. They blend fairly well with the existing wall color. The new curtains will hide most of the holes, but when the curtains are opened, some would show.
Fastex 207-080501-01 Hole Plugs for 1/8" Hole 1/4" Head Nylon Lot of 40 #5713
http://www.ebay.com/itm/262615419974
$9 for 40 plugs