I can't begin to count the books I've skimmed over and not completed a single exercise. LPTHW was really nice in the way it gave you nothing else to do but exercises. Perhaps something as simple as a small, tight-knit forum (plenty of free forum providers) & IRC channel (something like freenode #python-studygrp) can be useful to bust the barrier of "I'll just start on that exercise/project/book when I'm a bit less tired." Somebody shoots an idea of something they've been meaning to do and others can jump in with brainstorming, ideas, pair programming and general "let's just do it" attitude.
Hell, I know I've been meaning to write a python script to draw a daily histogram of the creation times of Opera bookmarks, but I never got around to it. If I had a twin, I'd prod myself to hunker down and just write those <1KLoC.
So if anyone's interested in the group thing, just drop me a line so I can set it up tonight (CEST timezone here).