Okay, I just want to clear a few things up about porygon.  For one, He's
not the worst card in the game.  In fact, if you use him correctly he
can be a pretty good card (as with any of the other cards).  True, his
30 HP make him pretty weak, and he has no attacks that do any damage.
But the attacks he does have are cheap and quite useful.
Conversion 1:  For one energy of any type, the defending pokemon's
weakness (if there is one) can be changed to any other type other than
colorless.  The card doesn't say "change to any pokemon type in play" or
such.  This can make water pokemon weak vs. fire, fire weak vs.
electric, etc.  Just choose the same type as your deck, and voila!  You
can now do twice as much damage a turn to that pokemon.  Of course, you
have to retreat porygon first, and he could get K/Oed during that turn.
Attach a defender to get around this possibly.  And the effect lasts
too.  Nowhere under the attack does it say that the effect is ended when
you bench either pokemon.
This same attack could also be used to get around resistances as well.
Say you have a psycic deck and you're facing a colorless deck.  All of
those pokemon (except for birds) are resistant to psycic, and most are
also weak vs. fighting.  If you have a porygon, just use conversion 1
and change the weakness to psycic.  This cancels out the resistance, so
you can now do normal damage to colorless pokemon with psycic.
That's all I have to say, other than this:  Take a good look at a card
before you say it's bad or good.  Every card has a weakness, and
everycard has a strength.  When you look at it that way, everycard is
then roughly the same, for better or worse.  True, there are some really
lame cards out there, but even these have their different strengths.

Te'nala, AKA
sam@engelridge.com