what all do I need ( cables, cards, software) do I need to share my monitor with another computer?

What?????????

Some montiors have an aditional input. Sony has one. The only other option i can think of is Made by belkin this device is usually used for managing several servers with a single monitor keyboard and mouse. Both of these options are more than 300.00 US. You would do better to spend you money on a new monitor. Ebay has several used 17" flat trinitron monitors with buy it now options at 110.00 US. By flat i dont mean plasma or lcd display i mean flat glass. Reduces glare and provides a better picture. These are the only two options i know of. You may be able to find a monitor cable with 2 male to 1 female display connectors. then you can plug the two PC's into the monitor, no way to switch between the two other than keeping one PC off. If you cant find a cable and your handy with a tool box you may be able to go down to radio shack or the pc store and find the neccesary connectors to create this cable. I would be careful, i dont know what having two PC's powered up and connected to a single computer would do to it. could cause damage? Another thought is to search the local PC store for a cheaper version of the belkin device. Hope this helps

Assuming that you are not planning on using both computers at the same time, all you need is a VGA switch box, which can be found at your local computer store. Then you just need 2 male to male vga cables to plug into the switch box(main monitor cable goes directly to the switch box).

KVM switch...cheap non-manual ones on pricewatch start at $45, less the cables...Have a 4 port one that has been indispensable