TeX title and axe labels

First of all, i am blown away by the last two releases. Congratulations. I love TkAgg and the new TeX capabilities.

I have been feeling like a contour plot capability was missing from the current release. Since imshow is so much faster than pcolor, it would seem that it could do the job. How would you go about suppressing the colors altogether and plotting only the 'contours' (borders between different colors i guess)? If this is doable in a few commands, perhaps there could be a shortcut called 'contour', as in Matlab, to draw contour plots of a function of 2 variables?

Titles appear differently when they contain TeX commands, depending on whether or not they also contain regular text. For instance:

- title( r'$\rm{This is } \psi(\omega)$' )
   appears nicely, although the spacing in the "regular" text looks unequal on my monitor. But:

- title( r'$\psi(\omega)$' )
   alone, shows only the top of the symbols \psi(\omega)---it looks like the box that contains the text is placed too low, behind the plot. Same happens with [xy]label. Surprisingly, xlabel( r'$\omega$' ) works fine.

Also in the documentation for matplotlib.mathtext, are there dollar signs missing in the first example?

In the documentation for imshow(), i guess 'ColorMap' should actually be 'Colormap' (lowercase m)?! I couldn't find any 'ColorMap'.

A final comment, using gca().set_yticks( ... ) prints a large number of messages "<matplotlib.axis.YTick instance at ...>". There must be a print somethere.

Great job!