I can't access youtube at work, so I'm not sure which silicone case you are referring to, but I am using one that seems to be the most popular on ebay. It sells for about $5-$10 and you can easily identify it by a X marked on the lower right backside of the case.
This is the case:
http://cgi.ebay.com/FOR-HTC-TOUCH-DIAMOND-SPRINT-BLACK-SILICONE-SKIN-CASE_W0QQitemZ300277730337QQcmdZViewItemQQptZPDA_A ccessories?hash=item300277730337&_trksid=p3286.c0. m14&_trkparms=72%3A1205|66%3A2|65%3A12|39%3A1|240% 3A1318
Here is my review:
The case adds good protection without too much bulk. It has a good grip and stays on the phone well. The case covers the top of the phone by the headset speaker and, but has a cutout for that speaker and the light sensor. I have noticed that the case does somewhat cover the light sensor. There are cutouts for the stylus, microphone, usb port, headset speaker, loudspeaker, and the camera area. Getting the stylus out is sometimes a bit difficult and the volume and power buttons can be harder to press.
Pros:
- Good Protection without too much bulk
- Good feel and construction
- Great price, usually $5-$10 on ebay
- Stays on Phone well and does not obstruct the screen
Cons:
- Headset speaker cutout is not always enough for the light sensor
- Volume and power buttons more difficult to press
- Sometimes difficult to remove stylus