pad recorded audio with silence to make mixing easier

[xizar]

I use Mumble with Fraps while playing WoW, and want to start including the audio of our conversations in the videos I'm making for our raids.

Sometimes, though, our conversations get a bit blue and, in the interest of staying YT friendly, I'd like to be able to edit out some of the more colorful portions, so I've thought I'd save everyone's audio as individual files, rather than as a single one mixed down.

I've a problem, though, that my skills aren't so great, and I've been struggling in Audacity to try to line up the times that people login to make a "master track" with everything properly edited and mixed.

Is there a way to have Mumble save the audio files with padding so they all start or end at the same time (when I press the record button, or something?)

Fortunately, everyone's connection was stable, else I shudder to think what would happen when people login and out several times during an evening.

I hope my request for help was clear, and I appreciate your time.