One Click Conversations allows painless access to your recent Gmail conversations, in just one click. The demo below should explain things succinctly.
For a while this was pretty popular, and got included in Better Gmail. But then it ran into problems when Gmail changed several times, and is currently in a state of disrepair.
But the silent video below should give you a pretty good idea of what it does. Not the greatest demo video, but hey, in 2007 we didn’t have all these nice tools. Times were tough, man.