matplotlib Code

#!/usr/bin/env python

from matplotlib.widgets import Cursor
import pylab


fig = pylab.figure(figsize=(8,6))
ax = fig.add_axes([0.075, 0.25, 0.9, 0.725], axisbg='#FFFFCC')
#ax = fig.add_subplot(111, axisbg='#FFFFCC')
canvas = ax.figure.canvas

x,y = 4*(pylab.rand(2,100)-.5)
ax.plot(x,y,'o')
ax.set_xlim(-2,2)
ax.set_ylim(-2,2)

# set useblit = True on gtkagg for enhanced performance
cursor = Cursor(ax, useblit=True, color='red', linewidth=2 )

pylab.show()