PK320 HDMI Input Discussion
The PK320 has a mini-HDMI input. It works as advertised, however, one thing to be aware of: Not all cables will work. (Optoma does not provide an HDMI-mini cable.)
Today there are some very thin HDMI cables out there pioneered by a company called Redmere. They sent me several and I've been using them at various times for about a year. Their technology is now sold under many brand names, including, I believe, some Monster cables. (The actual 10 foot cable, is no thicker than an iPhone charging cable - extremely thin compared to anything else), (think thinner than a strand of spaghetti). I normally carry a standard HDMI and one with HDMI on one end and the HDMI-mini on the other, when I travel. I often hook up to room LCDTVs when possible.
A super thin HDMI - HDMI-mini cable that weighs less than an ounce would seem perfect - if it works. The thing is the technology that helps make it work draws power from the HDMI at the display end (normally power, when needed, is pulled from the source, not the display). The PK320 apparently doesn't provide that power at the display end so this smart cable can't get the juice it needs to work. Bottom line, you'll need a more standard thickness and weight cable
Audio
Has a 1 watt speaker which won't rock anyone's house, but there is also a 3.5mm audio headphone jack. If you want more audio, feed the output of the headphone jack to a powered speaker (there are some pretty impressive very small ones), or a regular audio system, then you can rock athe house.