I use matplotlib fairly frequently in my research, it rocks. However, the fact that the MacOSX backed doesn't let me use 'Cmd-Q' to close things down is annoying. So my solution is a combination of pycario and preview with a little AppleScript through in for fun. I program in Eclipse with PyDev, however I run my python programs exclusively from iTerm. Hence, I'm used to cmd-tabbing back and forth between iterm and eclipse. However, when I run a program that opens up a gui, such doing "pylab.show()" things get annoying.