The answers to both of your questions depends on the signal type. Are you talking about analog VGA (15-pin Hi-Density D-Sub connector), and a CRT monitor?

In order to answer properly, we need to know:

1.) Computer video output type(s) (Analog VGA, DVI, HDMI, Composite video, S-Video)

2.) Monitor type(s) (CRT, LCD, etc) and what input connections they have.

3.) Distance from computer to 2nd monitor.

Tom

For locating a remote workstation at distances up to 1000 feet you can install a KVM extender. (Keyboard, Video and Mouse)

http://en.wikipedia.org/wiki/KVM_extender

Who do you want to spy on?

Actually, what you are doing is a fairly common thing. We supplied a large sawmill with monitors spaced about 150 ft each way from the computer. The signal ran over Cat 5 cable and it worked good.

Look for a 2 port monitor signal splitter. They are sold by a lot of companies.

Randy

You can of course buy a graphics card with 2 monitor outputs, or in the case of a laptop there's usually a monitor output in which you can split the screens in the graphics software. There's nothing special about a video signal from a computer, personally I would just knock up an extension yourself using good quality screened cable and I bet it works fine, if it doesn't then it's not much of a loss just a bit of soldering experience.

Yes and yes

Yes. Just install a second video card. A screen will pop up and ask you a question. Follow the instructions, and you will be able to drag the image from the main computer to the second one, and multitask from both.

No room on the board for another card. That is why I specified an external device.

I do not recommend the dual video card as a solution. 1st, the price will be close to the splitter box. 2nd, that solution has you running signal over a VGA cable. You will loose signal quality with longer VGA cables unless you spend more money on a signal booster which will put you way beyond just buying the splitter box with the signal booster already built in.

I recommend the one using Cat 5 cable because the cable is cheap and it works great( price out long VGA cable and compare) You can buy splitter boxes for use with HDMI, DVI, VGA, ect if for some reason you can't or don't want to use the Cat 5. The biggest thing is that you need to do some research yourself on video splitter boxes to get what will make you happy.

Follow this link to the one shown below. http://pc.pcconnection.com/1/1/5038-black-box-2-channel-mini-cat5-splitter-extender-transmitter-ac600a.html There are many brands and many prices available and hundreds of places selling them.

2-Channel Mini-Cat5 Splitter Extender Transmitter

More From: Black Box Corp. Item #: 6499092 Mfr. Part#: AC600A Availability: On Order Est. Ship: Call for Availability

Overview Specs Reviews 2-Channel Mini-Cat5 Splitter/Extender Transmitter - AC600A

Mini Cat5 Splitter/Extenders enable you to easily place video displays such as monitors or LCD screens where you need them to display information such as schedules, menus, or advertising. Just plug a standard Cat5 cable, up to 300 feet long, between splitter/extender and a reciver unit. This 2-channel transmitter sends video to two remote displays. 2-Channel Mini-Cat5 Splitter/Extender Transmitter - AC600A

2-Channel Mini-Cat5 Splitter/Extender Transmitter - AC600A There are no reviews. Be the first to write a review. http://www.pcconnection.com/IPA/Shop/Product/Detail.htm?sku=6499092#BVSecondaryCustomerRatings Average Customer Review (0 customer reviews) 0 of 0 customers would recommend this product.

Good luck,

Randy

Checkout this thread—One Computer two peripherals

DVI Splitter VGA HDMI

This has been done many years ago try and Google a site.