[snovvman]

As far as I know there is no "proximity" sensor in the Diamond nor Touch Pro. By that, I presume you mean using either infrared, sonar, capacitance, or other similar technology.

The Diamond and Touch Pro DO have an ambient light sensor that is located adjacent to the speaker. The "fast sleep" feature is designed so that when the face covers the light sensor during the call, the screen will blank. This mimics the iPhone feature, which uses capacitance to detect the face (much more reliable).

It is well discussed that the CDMA Diamond (don't know yet about the TP, haven't tried it) does NOT turn off the screen like the GSMs do.

Funny thing--the people who have this feature don't want it, and those who don't have this feature do want it. I've looked at many registry settings and researched, but have not found a way to activate this feature.