One of the most interesting/subtle marketing moves Digium did on its phones is to put the phrase “HD voice” on the handset. There aren’t a lot of people who do that right now.
As I’m flipping through pictures and leftovers from IT EXPO East 2012, I see Denwa has its phone handset stamped with “HD” with some waves flowing out of it, but that leaves some ambiguity as to what it means. After all, there are people running around abusing the term “HD audio” in place of the (more proper) “HD voice.”
If memory serves, I’ve also seen the more stylized AudioCodes “HDVoIP” logo appear on some that company’s handsets/phones, but that gets into the whole trademark issue.
Hopefully more desktop IP phone manufacturers will take the simple expedient of putting “HD voice” onto handsets just to remind people the capability is there and available for use – instead of buried as a feature in a manual.