and here my absolute favorite one

:
http://www.farsidic.com/
if you press the right button (on
left-hand-side "farsi to english") you
can comfortably clicking the farsi letters
in to get the english translation of your
request ...
... but unfortunately it does not work so
nice in writing from right-hand-side to
left-hand-side ... this has to be repaired
on this side