Only just saw this topic, so I'd like to clarify what exactly happened in my battle that KP described. I had Swampert out, and LukeWar brought in his Dragonite. Anyone that battles in PWO knows that Swampert doesn't stand even a remote chance of beating Dragonite, so naturally the best option for me was to use Growl a couple of times to lower Dragonite's attack, thus setting up my next Pokemon nicely without worrying about taking too much damage from Dragonite. However, as many others have tried to do in the past, Luke tried spamming Dragon Dance, hoping that I would eventually give up using Growl (I didn't) so that he could boost his Dragonite so much that it would be unbeatable. Basically, had I used any other move besides Growl, it would have been as good as a forfeit in that battle. This back-and-forth of Growl and Dragon Dance went on for nearly 30 minutes!
Of course, this is just an example of the boosting problems presented in PWO right now. As others have noted in this topic, a strategy rapidly growing in popularity is to lower the attack stat of a Pokemon that is likely to only have physical moves (such as Snorlax), and then bringing in Dragonite or Scizor to boost itself with Agility and Dragon Dance or Swords Dance to the point where that Pokemon can sweep an entire team. There are ways to avoid this problem, but I won't get into that discussion. The point is that the back-and-forth scenarios of moves like Growl and Dragon/Swords Dance or Scary Face and Agility for what seems like an eternity is getting ridiculous.
As has also been noted by other players, TMs could help to solve this problem. However, PP is likely the most logical solution. Then again, I don't recommend PP for every move, as one of the best advantages of PWO is being able to train indefinitely without having to return to a Pokecenter just to restore PP. I do agree with Fonty's idea of limiting certain moves, namely all stat changing ones (e.g. Agility, Dragon Dance, etc.). I don't see the need for PP on attacking moves or status moves (i.e. sleep, confusion, etc.) until switching is fixed. Sure, players could still get stuck in back-and-forth situations, but at least you'd know they have a defined end point (when one player runs out of PP). I'll try and list the moves that right now should have the PP they get in the handhelds or similar:
Dragon Dance
Swords Dance
Agility
Scary Face
Featherdance
Memento
Growl
Belly Drum
Curse
Autotomize
Rock Polish