According to LAN Magazine, “85-95% of network failures are due in large part to cabling problems.”
As speeds and bandwidth increase, slight errors in installation CAN make the system non-compliant and MAY make a network useless so consider the following list of cabling tips:

• Don’t remove more of the outer jacket then is necessary to terminate.
• When terminating, don’t untwist conductors more then 1/2″ for CAT5e or higher cables.
• Don’t Run Next to Electricity:
  • Avoid electrical cabling and electrical sources.
  • Don’t tie cables to electrical conduits.
  • Don’t run communication cabling within 2 ft of electrical.
  • Always cross electrical at right angles.
• Protect Cabling:
  • Avoid sharp edges when pulling.
  • Use grommets to protect the cable when passing through rough openings.
  • Use low pulling force (25lbf or less), if using a pull string use one rated at 200lbf.
  • Make gradual bends when necessary (1″ radius min, 2″ recommended).
  • Don’t over tighten tie wraps.
  • Avoid using staples. If you must, use staples rated for use with communications cables (i.e T59).
• Use one wiring scheme – 568A (preferred).
• Always run all cables in a STAR topology.
• Limit runs to 295 ft (90 meters).
• Properly label all cables.
• Always use proper testing.
• Leave slack at the both the outlet (8″ min) and patch panel (10ft).
• Pull longest runs first working towards your shortest runs to reduce waste to
  an average of 15%.

One technique of extending broadband access to end users located beyond the serving radius is to use pair bonding. With pair bonding, the broadband access service is deployed using two DSL access lines where the sum of the bit rates from each line are used to provide the objective distance needed for access area. Alternatively, pair bonding can be used to increase the bit rate available to the customer for enhanced service quality.

The HDMI Specifications do not specify cable lengths. However, for long cable runs the following is recommended:
If you need to send a 1080p signal more than 25feet, or a 1080i signal more than 49 feet, active electronics will help clean up and boost an HDMI signal when it’s traveling long distances. You can purchase either a stand-alone booster or an active cable, where the circuitry is embedded in the connectors themselves. In both cases, the connection requires a power source.

HDMI over CAT5e/6:
Runs of up to 50 meters can be achieved by sending the HDMI signal over a run of CAT5e/6 networking cable, using special adapters designed for this purpose. These products incorporate booster and equalization electronics at each end of the path and require external power. Because of its tighter manufacturing tolerances, CAT6 cable is generally preferred over CAT5 in these applications. Stay tuned in March 2010 for more information about Suttle HDMI over CAT5e/6 products.

For more info on HDMI see: http://en.wikipedia.org/wiki/HDMI