I know there are other good graphics tools to deal with comparing and merging files, but I think that kdiff3 is really good, in terms of power, usability and speed. And it's cross-platform too, so I can use it on Windows and Mac (when I actually get a Mac, but that's not the point of this post...).
Fortunately we, kdiff3 users, are not hopeless. The author is coding a KDE4 version, and on the same bug page I linked above he tells us how to get it compiled from source:
svn co svn://anonsvn.kde.org/home/kde/trunk/extragear/utils/kdiff3 kdiff3
cd kdiff3
mkdir release
cd release
cmake .. -DCMAKE_INSTALL_PREFIX=
make
sudo make install
So I'm happy again now that hg merge (and hg qpush -a -m) gives me the nice and powerful kdiff3 3-way merge interface to merge conflicts instead of a "sorry, there are conflicts, please fix them" message on the console.

