The left mouse button in my beatiful mouse, the Logitech mx518, decided to stop working. I noticed this when I was losing very badly playing Team Fortress 2; things weren't happening when I was clicking! Naturally, instead of throwing it into the trash pile and ordering a new one, I decided to investigate further into the cause of this failure. It wasn't software, something was wrong with the button.
Turns out, nearly all mice use the same little tactile switches for their mouse buttons and they all have the same pinouts. Luckily, I had another, older, deader, mouse that I had pillaged for its infrared LEDs, and, it still had its mouse button switches. What's next? Mouse button transplant! A quick desolder and resolder later and I have my mouse working again.
Simply working is not enough, while I have it open I have to add at least one LED! The best place was on the Logitech logo, which looks really nice once I discovered its black coating rubs off to reveal this nice metallic finish. A quick dremel drill press and datasheet lookup on the IC sitting on the pcb (to find +5v and gnd) later and we have a mouse with a new glow.
The new button from the older mouse actual has more of a "click" to it and is much more tactile than the old one; I actually like it better. In fact, I like it so much, I might have to swap the right mouse button switch. See the whole thing with notes in the photostream!