HDMI is to replace all the other
video transfer methods today, it has a few challenges it must overcome. Long cable runs is one of those challenges.
Although there is no specified maximum cable length for HDMI, any distance over 50 feet can be difficult, or at the
very least, expensive.
Intelix has one possible solution. They just announced a HDMI over CAT-5 balun which will allow you to run two 150 foot CAT5 cables to connect your HDMI equipment. The device is HDCP compliant and is perfect for projectors or technology closets. It does seem odd to me that they choose CAT5, it seems that a single RG6 cable would have been a better choice.