Schmadic-
Good luck with your installation. I've got 4 TV's running on the same STB, and keep the resolution at 1080i. We used existing wiring to run coax from the STB to a 1 in, 4 out splitter. Main TV is a Pioneer plasma. Also have a little LG LCD panel, and the other two are SD sets.
Remotes: I use Harmony remote for main system. On other TV's, Radio Shack sells a remote extender system. Has a transmitter and receiver as described above by vinny07, and you can buy additional receiver units. I have receivers plugged in near each of the three extra TV's, and use the Voom remote when watching any of those. The transmitter unit is pointed at the STB, and it relays commands from the Voom remote. Works great, so we can choose any of 4 locations to watch TV.
As Ilya points out, the use of coax limits you to 480i on your peripheral TV's. I bought the LG television before I knew that. It is a nice little panel, and capable of 1080i--but not with a 480i signal. But the picture is very good, my wife would swear that it is HD, and she doesn't follow this forum--so I'm still a hero.