A few weeks ago a bug regarding the way we are signing our Mac builds was reported by a user of the Keychain Integration Services extension. I think this bug is an amazing example of how great our community is, and why they are so valuable to us.
This bug talks about a problem that exists on Snow Leopard and earlier where OS X will ask the user over and over again for permission for Firefox to access the system Keychain. The initial bug report has tremendous analysis of the problem, isolating it to specific OS X versions and comparing the signatures on them. Steven Michaud quickly jumped in to try to confirm and find a fix, but it wasn't until Julian Fitzell (the Keychain Integration Services developer) jumped in that the problem was fully understood. After he went to the effort of figuring out exactly what we needed to do it was relatively simple to fix the bug in a timely manner.
The reason this stands out so much to me is that because this is a problem that would only affect Keychain Integration Services users, it was (correctly) prioritized as low priority. (As much as we would like to fix every bug that is critical to everybody, it's not feasible.) Because Julian cared and was capable of helping us find the fix it was possible to fix this bug before Firefox 14 was released. Without his help it's very unlikely this would've been fixed so quickly.
So: thank you Julian and spinifer. You rock!