I don't like the looks of the pylab graphs, I wouldn't put them in a paper. However, there's also PyX (http://pyx.sourceforge.net/index.html) which is a little more verbose in usage but makes very nice "latexy" plots that go well along with a latexed paper. And it can do some really advanced stuff, too, that I wouldn't even know how to begin thinking about doing in pylab.