Lidoderm
"My doctor gave me a couple of these to try out before I filled a script for them (for shoulder and lower back pain). I cut them up because they are HUGE. Put ½ on my back and ½ on my shoulder the first night. I hadn't slept more than a couple of hours a night for the last week because of my back (that's with oxymorphone and oxycodone) and WOW, slept like a baby! Took my back pain from an 8 to a 3. I didn't even notice the patch was there. 



Now for my shoulder though, these things aren't very sticky and so the movement makes them come off in just a couple minutes. I taped it down, but it's kinda bubbling in the middle and I'm having a hard time keeping it in contact with my skin unless I'm holding my arm just so."