The bouldering in PMB is not great. The 'best' area, and the only one with approved access, is King Solomon's mine. There is also a guide by Greg Streatfield. I thought it was on this site but can't find it -- he would be the best person to contact.
There is not much quantity in PMB but there are some Gems. At Ferncliff, there is damn cool problem called 'Snookered'. If you are standing at the clearing near the dam (where all the huge boulders are) facing up the hill follow the trail left instead of right and go over a little knoll (it used to be clear of trees but they may have re-planted (in which case it will be hard to find). It is the lone boulder split in half (the other half has been quarried). It is not in the forest so if you wander too high you are in the wrong place! The problem goes up the rounded arete. Not hard but you get into a position where you can't move (hence the name) and the crux is trying to get out of this position (very bleauesque. har har) The boulders near the dam 'may' possibly reveal some high-balls if you are prepared to clean off the lichen (but then you would need to get permission methinks). But round the back (out of view) of these boulders there are a couple of short arb problems.
Otherwise, there are some rad quarry problems at the Quarry shopping center in Hilton. These problems are almost directly below the Center facing the dam. To get there park by the gym and walk downhill and then right into the clearing. Walk directly down the road leading to the dam. At the end of the road follow the path right. The 'crag' forms a ^ the good problems are on the left side. There is jump problem (big), an arete (very good (techinical, you have to do this rad 'double move' hopping your left hand and left foot up the arete at the same time!!). The hardest problem is to the right of this obvious good arete problem. It goes straight up a very thin crack opening into two holds which appear unusable until you sort out your weight and ends on quick hands deadpoint. Very cool. Careful the rock is quite brittle so don't go soloing the high stuff on the right. Also, even if u are feeling severe withdrawl don't bouldering /soloing at World's View. Loose rock nearly killed a friend of mine.
But if you want to go somewhere where you have more to choose from than like 5 problems go to Swinburne. There are some really good problems here (also some really shite ones).
Anway, there is also a new very good crag being opened up at Howick falls (directly below the abseil) so if you can bear to tie into a rope??