Sorry. I just read the initial question that I posted, and realize that it's a bit vague AND ambiguous (a double whammy there for you).
I'm looking for a command in Logic, if there is one, that would allow you to move ONLY the waveform within a region forward or backward while keeping the region itself in the same position.
In visual editing, if you have clip 1, 2, and 3 (cut and edited together in that order) and you want to keep where the cuts specifically take place, but you want to, for example, see a different portion of clip 2 (a few frames earlier, say), then you use the slip tool, which, again, allows you to do this very thing (move only the visual portion of clip 2 one way or the other without loosing the integrity of the cut itself).
Hope that helps clarify a little bit.