Do ground lifters alter sound?

Beyond getting rid of hum, can they degrade what a good cable is doing?
My dad and I installed new gear from Esoteric, VPI, and Audio Research along with all Audioquest cables including the mid-level power cords and we had hum so we lifted the grounds to curb the problem, we used cheap lifters found at Wallmart so I got curious of others opinions, are higher quality lifters available and if there are wich I assume is the case, do they make a diffrence in sound?
Half of me says such a small surface area in the lifter wouldnt affect sound but the other half thinks it is a bit silly to put a $0.25 lifter on a $300 power cord.
Any thoughts appreciated...............Chad
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Some manufacturers -- PS Audio, I think, and others, make their PCs w/ AC plugs that have a removable ground pin. That would be the simplest solution. Another (easily reversable) fix would be to open up the PC's AC plug and disconnect the cord's ground wire from the plug's ground terminal, and cover the end of the disconnected ground wire with a bit of electrical tape.

I agree w/ the half of you that doesn't want to add another set of contacts;--)
Thanks guys, do you know of any "high Quality" lifters?
There are no high quality lifters for two reasons:

1. It is a contradiction in terms, and

2. They'd be so expensive you'd be better off spending you money on:
a. Dedicated circuits
b. Power regenerator
c. Balanced power unit
d. or all three ;--)
Your language caused me pause. You are talking about cheater plugs, I now suspect. There really are no quality cheaters, although I have heard that Siltech used to make some. Many will strongly admonish you to not lift the ground for safety reasons.

I have had instances where I had hum problems, where lifting the ground would help. In all instances other than on the vinyl source, I have ultimately found the problem and undone the need to lift the ground.

Reversing the ground is another question. I wish I had a quality product that would easily allow me to do this.