I've got hundreds of these bogging down my machine:

bradyh   28812  0.0  0.0     0    0 ?        Z    Mar22   0:00 [sh <defunct>]
bradyh   28813  0.0  0.0     0    0 ?        Z    Mar22   0:00 [sh <defunct>]
bradyh   28814  0.0  0.0     0    0 ?        Z    Mar22   0:00 [sh <defunct>]
bradyh   28815  0.0  0.0     0    0 ?        Z    Mar22   0:00 [sh <defunct>]
bradyh   28816  0.0  0.0     0    0 ?        Z    Mar22   0:00 [sh <defunct>]
bradyh   28817  0.0  0.0     0    0 ?        Z    Mar22   0:00 [sh <defunct>]
bradyh   28818  0.0  0.0     0    0 ?        Z    Mar22   0:00 [sh <defunct>]
...

Is there any way to get rid of them aside from rebooting?  No form of kill seems to work on them.

Thanks,
Brady