In an earlier post I mentioned I didn't know how to search-n-replace in multiple files using Emacs.
It turns out there is no good way to do that out-of-the-box. But after an intense Google session I found this entry in the Emacs Wiki: GlobRep.
There are other options as well, mentioned on the SearchAndReplace page, but that page seems a bit chaotic, and I'm quite happy with GlobRep.
The other day I also discovered (well, discovered... I needed the functionality and looked for it) ediff, and especially ediff-directories. Very, very powerful diff and merge functionality, usable in a vague kind of way. In some way it's even better than Araxis Merge which is an accomplishment.