Well if you work in IT and you need a quick fix, look no further than that giant spool of CAT6 UTP laying in the corner of the server room!
(as is customary....sorry for the crappy pictures but they were taken on my phone while standing in my server room trying to fiddle my button back on to my pants....i'm so glad that i've got a lock on the door and no windows haha)
Step 1: Supplies
A button (hopefully THE button)
Some CAT6 UTP (or any solid core wire of a small guage)
Some pliers (or a way to cut your wire)
Step 2: Poke a hole
I found that poking the hole through the pants RIGHT before you thread the UTP strand through the hole is better since the threads have a habit of closing back up as you try to monkey with your pants (while wearing them).
Step 3: Prep your UTP
i also found it to be a good idea to strip a small bit off the end of the strand
Step 4: Thread your UTP
I started threading from the outside to the inside, then passed the wire back through from the inside to the outside, but you can do whatever you want