Ok lets says I have a computer that has HDMI and 2 monitors that has HDMI ports. And I wanted the one computer on both monitors. And I wanted to put that computer also to a TV?
You would need a splitter in that case: http://www.newegg.com/Product/Product.aspx?Item=N82E16882200023. The best thing though would be to have a video card that has either 3 HDMI ports or 2 HDMI and a DVI port so you can use a DVI to HDMI port in one of the cases. I'm assuming that you would want the three displays to be used for extending your computer's desktop for more space, if so, then you would need three ports on your video card.
However, if you're just looking to duplicate the display of one monitor to the TV, then the splitter would probably be your best bet.
My Computer
OS
Windows 7 Ultimate x64 SP1
CPU
Intel Core i3 530 2.93 Ghz Clarkdale
Motherboard
ASRock P55 PRO/USB3 LGA 1156
Memory
4 GB OCZ DDR3 1600 (PC12800) Low Voltage Desktop Memory
Graphics Card(s)
Nvidia GeForce GTX 550 Ti with 1 GB of RAM
Sound Card
Realtek HD ALC892
Monitor(s) Displays
20'' eMachines E202HDbmd Glare Panel Widescreen
Screen Resolution
1600 x 900
Hard Drives
Western Digital 1 TB Caviar Black Edition (7200 RPM) SATA
Hitachi Deskstar 500 GB (7200 RPM) SATA
Samsung SpinPoint 400 GB (7200 RPM) SATA
PSU
Rosewill Xtreme Series RX750-D-B ATX12V v2.2 & EPS12V (750W)
