You can get this set of free wings at the Marketplace. They are also in my mini-hunt going on at my sim - read more about that at this blog post. This hunts ends Jan 1st so get these while you can.
Also ending soon - the Limited Edition Holiday Fairies - Details here! They also are going poof on Jan 1st. If you want something really rare - consider the gold fairy. We've only sold 3 of those, so there will be VERY few in world.