I have used an awl to put holes in the cups and the 32oz deli containers.  I have to admit, it is a pain in the butt doing it this way. 

But the real issue is the size of the hole it makes which is not very large and it  leaves the plastic pushed out (like an explosion) around the hole.  I put about 5 holes on the bottom and  12 on the cup side and 16 on the deli container.  Do you think this is enough?  The trees are doing OK but I get concerned about the lack of drainage when I water them.

Should I just leave them alone since they are doing OK? 

I have lost one out of 25 or so that are cupped - I think it was do to not watering enough after I cupped them.  I tried putting it back in the sp moss to save it - when I checked it last night it was not pretty.  I still have 3 of that variety so it will be OK, I just don't want to lose anymore.

Thanks

i found out different cup even in same size might need different number of holes. my previous 16 oz cups were fine with 3 holes on the bottom, using peat pot method. then i changed to thicker 160z cups with different rim shape. this ones seems to retain more moisture and i saw a mold between the cup and the peat pot. now i put on 4 on the bottom. however, i'm thinking it might also need few holes on the side.

i use 1/4" drill bit for the bottom. i'll probably go with something much smaller for the side. the balance should be where the soil will retain enought moisture, but not so much that it will rot the root.

3/16" has worked. Some will get plugged up with the perlite. If you stack 3-4 together, they are easier to drill through (makes them stiffer)

If you leave the pieces of the 'explosion' on, when you sit the cup down they may cover up the hole.  Drills and melting don't leave those pieces.  Any cheap electric screwdriver will work.  A drill or rotary tool will work faster.  Use a 3/16" bit as Jon mentioned.  A hot glue gun can be had for under $5.  Just use the edge of the front against the outside bottom of the cup to make what looks like a slot.  A soldering iron works faster than a hot glue gun.  If you have the $$ the dremel (rotary tool) is the most versatile.

some dollare stores have soldering irons for $2 .i bought mine at Harbor Frieght for $3

AUSTIN

I used 11/64 inch drill bit, eight holes in the bottom of a 32 oz deli container. 

I use a soldering iron. For the 32 oz cups/deli containers I find that 4 holes on the bottom and eight holes in 2 rows of 4 staggered on the sides works well for me.

* Make sure you are in a well ventilated area when using the soldering iron as the burned plastic is probably quite hazardous and it can produce a lot of smoke.

Thanks gentlemen!  I'll see if I can get to a dollar store before I go to work.  I noticed on the 16oz cups the edge of the bottom actually sits on the table where the middle area of the bottom is raised a bit - like a bump into the cup.  Water collects in the edge area - I hope I don't lose any from over watering :O