If you only have VGA available, however, this is a bit tricker. This is a different story because now you have to convert that analog VGA signal into a digital HDMI signal (there is no analog-version of HDMI as there is with DVI, aka DVI-A).

Now, however, the conversion is possible with a VGA to HDMI converter. These are a bit more expensive than a passive little converter because this analog to digital conversion is taking place. While ideally you should connect a VGA port to a component (or other analog-type connection), you shouldn’t see any loss with the analog to digital conversion - you just end up paying a bit more.

Sewell Direct offers a handy guide on VGA to HDMI converters.

When shopping for an HDMI splitter, you have a few difference choices. For instance, you may be able to get by with just a small passive cable - this would limit you to two screens, but is great if you just need an additional display in a tradeshow booth or in a retail store.

Active splitters are much more expensive than passive cables, but give you the freedom of adding many additional displays without any risk of signal interruption. These are commonly used in retail settings, sports bars, casinos - basically anywhere you would expect to see several mirrored displays.

1. Is HDMI the best interface? Obviously the answer is subjective - many people still swear that analog signals are higher quality than digital signals in the same way that many audiophiles still maintain that their old vinyl sounds better than new digital music formats.  Here are some of the facts:  HDMI supports all consumer HDTV resolutions including “Full HD” 1080p.  HDMI uses HDCP content protection method to guarantee that you have a perfect signal tranfer from your source to your display, (a feature that is not available over analog connections).  HDMI can support up to 8 digital audio streams, full surround sound, lossless audio, TrueHD and DTS-HD audio.  Both video and audio signals are sent over a single cable with a USB sized connector.  With HDMI you can be assured that you will be getting the best video and audio available over a single and simple cable.
2. I have an analog source - should I convert it to digital for better quality? No! If your original source is analog there is no benefit to digital conversion unless your TV or monitor will only support a digital input - introducing any type of conversion adds overhead (or noise) that will possibly degrade the signal. The best you can hope from a good converter is a comparable signal to what you would expect without the converter.
3. Is there a difference between a high-end HDMI cable and a regular one? As much as the marketers of HDMI cables would like you to think there is a difference, in general there doesn’t seem to be many. HDMI carries a digital signal - the source either receives the signal in it’s entirety or it doesn’t receive it at all (which you will know really quick). The one difference seems to be the connectors - if the connectors are bad or too cheap they may be damaged with repeated use. That is not a common problem - if you’re worried about it just buy 2 cheap HDMI cables upfront - they will still be much cheaper than an expensive one and you can always use the other if the first one dies.