well, the only way I can do the treadmill is if I have the t.v. on. I turn the volume way way up and just start walking. I usually turn on a talk show or something I am interested in to keep my attention focused on the show, rather than on how long I am walking absolutely nowhere!
Also, I used to BLAST the stereo to some of my old favorite 70's tunes and would sing along loud and walk. I would suggest that you do this when no one else is around...you sort of look and sound silly doing it!