Here's a proposed janitor project if anybody is interested:

The current gcc 4.0 snapshots include some more warnings in -Wall
and changed some existing ones which makes a kernel compilation quite noisy. 

The project would be to fix all these warnings.

Short howto: 

Get
ftp://gcc.gnu.org/pub/gcc/snapshots/4.0-20041219/gcc-core-4.0-20041219.tar.bz2

Untar it and compile with 

mkdir obj
../gcc-*/configure --disable-checking --enable-languages=c --prefix=/usr/local/gcc4
make bootstrap
<as root> 
make install


Then compile an uptodate 2.6 kernel with:

make allmodconfig
make CC=/usr/local/gcc4/bin/gcc 2>&1 | tee LOG
grep warning LOG 

You'll see lots of warnings in LOG. Fix them all and submit patches
through the usual janitor channels.

-Andi