The only problem with using Audacity is that you have to save the results in order to use the change, I think. With the tools I was talking about you can use them “on the fly” as the original mp3 plays. So they are much handier.
Couldn’t you use Audacity to add a click track between 2 sections? I mean, you can assemble mp3 recordings, I think (one after the other) or split them, I think. Maybe I’m thinking of something else…