Since we're talking about it, I wanted to share my experiences with the Mini USB port on the Eris.
The Eris will accept Mini USB style-B connecters (white) but I've had trouble with this a couple of times. Once, my PC had difficulty staying connected with it. Twice, I had trouble charging with the generic cables. Once was from the PC, once was from the supplied HTC charger (but not the HTC-supplied cable)
The HTC-supplied cable (black) is much better at staying connected. But it isn't "improved" in my opinion. The matching port that accepts both styles is very loose with the more popular Mini-USB style B. In my opinion, that makes the whole concept of "unique, yet compatible with other popular styles" somewhat useless. I can't use the cable that came with the phone with other things like my Canon ELPH, my PS3 controller, etc. So I might as well take the cable wherever I go with the phone.
Does anyone know where I can get more of the HTC-styled USB cables? Surely it is not proprietary, I SWEAR I have seen this style elsewhere.