I am still learning but have been experimenting (with good WAF). I have a two story home.
General HA wiring.
Basically have a "run" of cables which go from the basement to the attic. In order to get them to run I drilled up from the basement into the first floor. That wall near the top I have an 8" speaker which I use for HA. On the second floor near the bottom on the floor I cut a 2' X 2' access panel. This is in one of the bedrooms and I made the panel aestically pleasing. At the top of that wall I have another HA speaker. In the attic I put a 2"X4" piece of wood to the roof. My attic allows me to stand up in that the center is over 6' in height. The hardest to deal with is the run from the first floor to the second floor. It is over 12".
This run of cables has multiple CAT5 cables (different colors) used for Network (including POE), alarm, temperature sensors, serial connections, etc. It has multiple 4 wire cables used for audio, multiple RG6 used for cable, RF, satellite.
Touch screens - I use multiple setups -
#1 was an experiment. It is an all in one 12-13" screen integrated into a 2.5' wall in the living room. It looks nice but I circumventing some basic "rules" in getting it there. This wall is a plumbing combo, stack, return and supply wall being about 8 foot wide X 8 foot high X 2.5' thick.
Garage touch screen - easy because of WAF - I have an 8" touch screen here connected to a mini PC in the basement. I passed a VGA, USB, power (12VDC) and audio in a run less than 5 feet. The mini PC is a 1.4 Celeron about 8"x8"X2". It runs 24/7.
Main floor touch screens - passing same as garage using same type of PC down to basement.
2nd floor touch screens - same as above but PC's in attic.
Experimenting with 9 pin to 15 pin to Cat5 VGA cables - works and allows small holes - so use Cat5to9PinRS232 connected to a 9PINto15PIN adapter. Works.
Personally I do not watch much TV.
In the kitchen Combo TV/PC - similar but different. The Kitchen LCD is a 15" flip down (from counter), It is used for "in house video" (TIVO etc), it has its own DTV box and it recieves direct RF TV. In addition it is a VGA monitor. This is connected to same micro PC mounted in the basement with a small wireless keyboard. This run is using a "Rapid Run combo VGA/Audio 10' cable" - this allows a small .5" hole for the VGA video run. Only future clean up may be moving the DTV box away from the kitchen counter to inside lower cabinet and using an RF blaster. (already using an RF blaster for Tivo here).
Working on a second combo TV/PC for dining area of kitchen - this would be same similar setup to counter but would be a 19-21 inch LCD combo LCD mounted on the wall at kitchen dining room table height on a small angled wall which faces the table. This is a bit more difficult because it is an outside wall.
I have tended to drift from original topic and rambled a bit....