However, many armchair linedrawers don’t realize the restrictions the real linedrawers are under from a) the real world of politics and b) the courts. In any event, the Listmeister’s List Dump blog has an “Objective Redistricting” plan; see also Andrew Gelman’s post on the Statistical Modeling, Causal Inference, and Social Science blog:
P.S. Ted Dunning suggests a different solution (see comments below): move the district lines randomly after every election. I like this, since it seems cleaner to implement from a constitutional perspective. Also has the advantage of allowing the districts to equalize population more frequently, and, beyond this, it puts less pressure on each redistricting to be super-balanced, since the lines would be redrawn every two years.