One other option:
If you register your phone on samsung's site, they should send you an Email with a 50% off coupon (for products that cost $50 or less). They sell the Samsung wireless charging cover for $19.99 (after 50% off). It adds a little more thickness to the phone (approx 1mm from what I could tell).
The link from halon in the previous post leads to cheaper alternatives on eBay ($12 or so) - and they ship from China. Not sure about warranty etc - but those should work with the regular phone back cover.
It is a Qi receiver, so should work with any Qi charger.
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