I know some of you will flame me for this, but until you study how easy it is to damage a component with static, you are dangerous to anyones computer you work on.
I used to think that just touching a case would be fine. Then I took a mandatory class at my job (Boeing Helicopters) when I was going to be installing and removing black boxes from the aircraft.
The class was on the dangers of electrostatic discharge to sensitive electronic components. I found out that even if you touch your case, you can still have enough static left in your body, or your clothes that can destroy your component. The item might even work for a month or so and seem fine, but what happened was that you caused microscopic damage and now after a period of time the voltage surges that happen every time you power up a system will cause it to fail. When I told my instructor that the common practice for most do it yourself computer builders was to just touch the case, he just shook his head and said " I know". Then he went on to explain how stupid it was to do that. He said that it only takes a couple of microvolts to destroy a component. And you can get that just by shaking your head and getting the static build up from your hair.
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LATENT FAILURES occur when ESD weakens or wounds the component to the point where it will still function properly during testing. However, over time the wounded component will cause poor system performance and eventually complete system failure.)[/FONT]
So to all of you that wonder why a component just seemed to fail out of nowhere. It's probably because you did not properly protect your system by grounding yourself and the case.
You should NEVER place your cards/devices on any metal or conductive table or case, you should never place your parts on anything plastic. Be aware that even though you have just touched your case, just moving around will cause more static to build up from the clothes you are wearing, especially if it is cold and you have your furnace turned on. The lower the humidity level the higher the instances of electrostatic buildup. Or on very hot low humidity days.
So even though you have removed your socks, the shirt or pants you are wearing will still build up static.
With out the case being grounded to a proper ground, when you touch the case releasing the static built up in your body, it has no where to go but into the case which can cause electrical components to short out, since more than likely it is sitting on your carpet, or on a table that has Formica or plastic on it.
It is best to ground yourself to a earthed/ground and NOT to your case. After all you want to get rid of the static before touching your parts or case.
Really, anyone that tells you it's ok to just touch the case, really does not have a clue about ESD (electro static discharge)
If you really want to do yourself and any customers you have a favor, set up a workstation that has multiple grounds.
While the following link is mostly for the military, it gives some good information.
http://www.dscc.dla.mil/Offices/packaging/ESDS.html
Here is a link that shows how to set up a workstation. While a ESD monitor is nice, for the common home setup I really do not think it is worth the cost. Ditto with the ones on the shoe.
http://www.newark.thinkhost.com/bra...lutions/How_to_install_an_ESD_Workstation.pdf
Other Links follow
http://www.static-sol.com/ESD_Solutions/ESD_Solutions.htm
http://www.static-sol.com/library/articles/ESD_damage.htm