Bulk update (special Ex-Lax edition)

Myer 
http://www.nongnu.org/myer/README.html
Myer is a "semantic highlighter" for C code, which "colorizes identifiers 
and constants to show their marginal cost to the program's coupling and 
cohesion metrics", by "running the preprocessor in reverse". The idea is 
to focus review by highlighting parts of the code particularly likely to 
contain bugs.

convertfs 
http://tzukanov.narod.ru/convertfs/index.html
This tool converts filesystems (e.g. ext3 to reiserfs) in place without 
needing space for two copies. It does this by playing clever tricks with 
sparse files. "You can convert from virtually any filesystem type to 
virtually any one as long as they are both supported by Linux for 
read/write, and as long as primary filesystem supports sparse files." 
(Submitted by Ville Herva.) 
See also Parted <http://www.gnu.org/software/parted/parted.html>.

VSDB 
http://repetae.net/~john/computer/vsdb/
VSDB turns Unix filesystem guarantees (even the weak ones offered by NFS) 
into a transactional database without using file locking or a shared 
server process. It's particularly good for medium-sized, rarely updated 
system databases (think aliases.db).

Filelight 
http://methylblue.com/filelight/
Filelight renders a cute interactive visualization of disk space 
consumption. See also KDirStat <http://kdirstat.sourceforge.net/kdirstat/>.