Okay, well the installation is complete. I purchased the following cable:
It came late last week, and I pulled the cable under my carpet this weekend. Everything went very smooth. I am glad I had the right tools... from home depot, I bought a 25-foot steel "fish tape" for about twelve bucks. I was able to "fish" this under the carpet from one side of the room to the other, attach the Atlona flat HDMI cable using duct tape, then pull the cable under the carpet. Once the cable was under the carpet, I was able to drill through the baseboard and insert the HDMI cable into the wall.
I now have HDMI running from a wall plate behind my AVR/Cable Box, through the wall, out the bottom of the baseboard, under the carpet, back through the baseboard on the other side of a 15-foot room, up the wall, and to a wall plate just behind my projector that is mounted about 9 feet up on the wall.
The installation was fairly easy. I'm no expert and it took me just a few hours to get everything done. Now, there is about 1/2" of cable visible from where it comes out under the carpet into the hole in the baseboard. It wasn't possible to keep the cable completely hidden because just behind the baseboard is a solid 2x6 pressure treated lumber that is attached to the foundation of the house. For me, this isn't a big deal because one side is behind all of my equipment and the other side is behind our couch.
Overall, the installation was painless and the cable does what it is supposed to do... my signal now goes from the front of the room to the back without a visible cable (well, except for the 1' cable going from the wall outlet to the back of the projector, but that doesn't count.
If anybody has any questions about this cable, feel free to shoot me a PM or ask here in this thread. If anybody is considering buying this cable and isn't sure, don't hesitate. The quality of the cable is excellent and so far I have not had any problems with it.
I would also like to add that while you can feel the cable under the carpet, it is very insignifigant. I can barely feel it, and I don't have the best quality carpet and pad. I'm sure with a thicker pad it would be harder to feel the cable.