I have a little old Canon SD200 point-and-shoot, which is a decent camera. unfortunately, i've (ab)used it quite a bit, lugging it everywhere in my pocket or in a bag and even sending it up in a kite (and, uh, bouncing it off the ground on the way back down sometimes).
Unsurprisingly, things occasionally fail when you subject them to harsh
conditions, and for a couple months now, the lens has failed to retract,
showing a message "E18" on the screen and refusing to take pictures.
It turns out i'm not the only one with this problem, and there is actually a really nice guide with good photos for the SD300, which is a very similar problem. I'd been putting off fixing it until i had time to really focus, out of fear that it would take forever, but it turned out to be a really quick fix (i did "Procedure 1" in the step-by-step guide and it worked after about a minute of fiddling with the position sensor), and now i have my camera back!
So thank you, Greg Toews, for your excellent documentation!