I run a cat5 along with my video cables from my closet to the display wall. I find it helpful to install the antenna right on the back of the plasma. I usually have more problems with the HD cable box and no problems with plamas. Since I am already running a cat5 for a possible ir reciever or emiiter anyway.
I really like the new Liberty cable that sells an Mini RBG6 with 2 shielded 2 - C with ground.
DON'T BE FRUSTRATED, GET INTEGRATED! (From a custom installer)