The basic uses for a reflective Mylar emergency blanket are relatively obvious: shawl or blanket, ground cover, rain protector, sun shade.
What are some other uses? If you cut it up, will a big square of it make a good sling? Will it hold together if you place grommets on it to make more of a tent? Can it be easily made into a stretcher or something to move the incapacitated? Is there a way to make a safe hammock with one?
Let's have a contest to see how many different uses we can amass, keeping safety in mind -- example: if you suggest using as a baby carrier sling -- would you carry your child in what you might suggesting? How do you cut, roll, tie or wrap the blanket to make the 'new' use.
If you have used a Mylar blanket as something other than the uses in the first sentence above, let us all know in the comments. There could be some very frugal applications of the humble 'space blanket' that will replace more expensive items. At about $1 each, that could be a lot of savings.
Rules are that you can make simple changes, such as cutting or tying corners. You can apply grommets from simple kits and use parachute cord, laundry line, string or dental floss -- things that are in your normal emergency kit.
In the mean time, I'll try to think up a fitting but frugal reward for the top suggestions!