Not to long ago I was asking about the same question. Here is the reply
from David Gillett.
His recommendations for a brand name are in the middle of the post.
Mary


>The product you are asking about is a "switch box".  Your keyboard,
>mouse and monitor all connect to it, and two groups of extension cables
>connect it to your two PCs' ports.  A switch on the box lets you
>control which PC is connected to the real devices, and which sees
>simulated signals provided by the box.  [Some brandso of box use
>standard "extender" cables -- male at one end and female at the other --
>to connect to the PCs, others use male-to-male or custome cables.]
>
>  The unit I use is made by LinkSys; Belkin also makes good ones.
>
>  Such a unit is *often* referred to as a KVM (Keyboard/Video/Mouse)
>switch, and shouldn't be confused with a single-port A/B switch.  A 2-
>way KVM probably starts at about $120 -- still cheaper than a second
>monitor, and takes up a lot less space.
>The product you are asking about is a "switch box".  Your keyboard,
>mouse and monitor all connect to it, and two groups of extension cables
>connect it to your two PCs' ports.  A switch on the box lets you
>control which PC is connected to the real devices, and which sees
>simulated signals provided by the box.  [Some brandso of box use
>standard "extender" cables -- male at one end and female at the other --
>to connect to the PCs, others use male-to-male or custome cables.]
>
>  The unit I use is made by LinkSys; Belkin also makes good ones.
>
>  Such a unit is *often* referred to as a KVM (Keyboard/Video/Mouse)
>switch, and shouldn't be confused with a single-port A/B switch.  A 2-
>way KVM probably starts at about $120 -- still cheaper than a second
>monitor, and takes up a lot less space.
>

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