Step 1: Materials:
1 Memo Pad or Small Notebook
2 Small Rare Earth Magnets (only one shown in Picture)
Super glue (or tape works fine)
On to the build...
Step 2: Attach Magnet to Memo Pad
Note: Taping the magnet onto the pad works fine too.
Step 3: Attach Magnet to Pen
Hold the pen.
Put a dab of glue on the place you are going to put the magnet.
Place the magnet.
Hold magnet until glue sets.
Add a little extra glue on top, to ensure a good hold. (If you deem necessary.)
When you are done, try it out on the fridge to make sure the glue is strong enough and to make sure that the magnet will hold the weight of the pen.