It's also worth pointing out that Apple does have a program for recycling their equipment, and they'll even reinburse you with a gift card for certain things:
http://www.apple.com/recycling/
They're not unique in this respect, too. WEEE and RoHS compliance is basically mandatory for Europe, so that requires manufacturers to have a safe disposal system in place for their electronics.
They will even give you a rebate on HTC phones in some locations if you turn in any old phone. That's not a proper recycling program because it requires the phone to boot, but it does take a lot of old phones out of circulation.
HTC should probably add a recycling section to their main website, the international nature of their website probably makes that problematic because they chose to have all these little local programs rather than one big universal one.
They're not unique in this respect, too. WEEE and RoHS compliance is basically mandatory for Europe, so that requires manufacturers to have a safe disposal system in place for their electronics.
Samsung has a program with several local partners(http://www.samsung.com/us/aboutsamsung/citizenship/usactivit...). Motorola(http://responsibility.motorola.com/index.php/environment/pro...) and Nokia(http://www.nokia.com/environment/recycling/where-and-how-to-...) also have programs to recycle your old electronics.
HTC does not seem to have a consumer recycling program in place, at least with the quick Google searches I've done.
EDIT: I have been corrected, as my Google-fu is weak. HTC does have several programs in place. Thanks!