Guys - it's potentially possible to add Qi for just $16 with some minor modifications to the case - I'm about to attempt it with a receiver I got from Amazon using my 635.
Amazon.com: BLUBOON(TM) Universal Qi Wireless Charging Receiver Wireless Charger Receiver Film for Micro-usb of All Android Mobile (Narrow-interface Up): Cell Phones & Accessories
It looks like you need to make the hole in the bottom of the 635 cover slightly larger to accommodate the connector, but the receiver itself works like a charm - I just tested it .
I'll post pictures of the 635 when i'm done.
Amazon.com: BLUBOON(TM) Universal Qi Wireless Charging Receiver Wireless Charger Receiver Film for Micro-usb of All Android Mobile (Narrow-interface Up): Cell Phones & Accessories
It looks like you need to make the hole in the bottom of the 635 cover slightly larger to accommodate the connector, but the receiver itself works like a charm - I just tested it .
I'll post pictures of the 635 when i'm done.