There are two kinds of 'unneeded' packages: Those applications that you've installed without really needing them and unneeded libraries. Debian can't help you with the first (you have to find out which software you want and which not. You should manually go through the list of installed software using graphical tools such as kpackage).

If, however, you're talking about the latter, ie. libraries that are not required by any other package, then you're lucky. There's a Debian program called deborphan, which finds all these 'orphans'. If it's not installed on your system already, do so using apt-get install deborphan.
You can then automatically remove unnecessary software by executing

apt-get remove --purge $(deborphan)

Well, have a look at /etc/crontab. You'll see that it executes your cron jobs (daily, weekly and monthly) around 6 in the morning. If your machine isn't running all the time, the cron jobs won't be executed, if you don't boot your machine before 6 in the morning.
That's one thing. The strange thing - I admit - is however, why some log files are rotated and some not. I do not have a clue as to why this happens, but you should know that logrotate only rotates a few logfiles (specified in /etc/logrotate.d/. Other logs such as /var/log/messages are handled by the sysklogd cron script. If you manually execute it, it will also rotate the remaining log files.
The real solution would be to install a cron software that can handle downtimes (anacron etc. is your friend).

Suppose eth0 is the internal NIC. You would then edit /etc/default/dhcp and change the line

INTERFACES=""

to eth0:

INTERFACES="eth0"

Issue a /etc/init.d/dhcp start. The service should start without complaining now.

Well, I don't have a clue what exactly is going on here, but this usually helps: Open /etc/kde3/kdm/Xservers and change the line

:0 local@tty1 /usr/X11R6/bin/X -nolisten tcp

to this (and then restart KDM):

:0 local@tty1 /usr/X11R6/bin/X -nolisten tcp vt7

iptables uses klogd to log messages. In Debian, klogd by default sends messages only to the console, not to the syslog log files. This default behaviour can be changed by editing /etc/init.d/klogd. Search for the line

KLOGD = ""

and replace it with

KLOGD = "-c 2"

Then, restart klogd by executing /etc/init.d/klogd force-reload

This is quite a common debian problem. If you try to change your GNOME fonts via gnome-font-properties, your GTK apps will display beautiful fonts, but the fonts in KDE decrease in size as well and become unreadable small.
I actually have no idea what causes this weirdness, but there's one easy thing you can do: By default, Debian starts XFree in 100 dpi mode, which doesn't make much sense unless you have a really hugh monitor. In order to start X with 74 dpis, just edit edit /etc/kde3/kdm/Xservers. There should be a line looking like this somewhere at the beginning:

:0 local@tty1 /usr/X11R6/bin/X -dpi 100 -nolisten tcp vt7

Now just change the -dpi 100 statement to -dpi 75 or add it if not present. You also might have to change /etc/X11/xinit/xserverrc to

#!/bin/sh
exec /usr/bin/X11/X -dpi 75 -nolisten tcp

Restart your X server and adjust your fonts (they will be to small, as the dpi mode has changed).

First of all, it was an absolutely dumb idea in the windows world to format removable drives only on the 4th partition (ZIP drives still work that way). That's why we can't rely on the filesystem to be on the first partition (i.e. /dev/sdX1) as one would expect. The only real solution to this is to use the sysfs kernel interface together with udev (see next section for details).

A weird problem and I don't have a clue about the reason for this to happen. However, have a look at /etc/pam.d/kdm. It should have the following lines:

@include common-auth
@include common-account
@include common-password
@include common-session

auth       required     pam_nologin.so
auth       required     pam_env.so
session    required     pam_limits.so

Now, either open /etc/pam.d/gdm as well and copy and paste its content into /etc/pam.d/kdm or change the latter to the following:

auth    requisite       pam_nologin.so
auth    required        pam_env.so
@include common-auth
@include common-account
session required        pam_limits.so
@include common-session
@include common-password

Relogin into KDE and your locales should work.

Older NVIDIA drivers don't let sysfs know that an NVIDIA card is present, hence udev has no chance to create the device nodes. Newer drivers should solve the issue, otherwise you can also create the device nodes yourself using this little script:

#!/bin/bash

for i in `seq 0 7`; do
   mknod /dev/nvidia$i c 195 $i
   chown :video /dev/nvidia$i
   chmod 660 /dev/nvidia$i
done

mknod /dev/nvidiactl c 195 255
chown :video /dev/nvidiactl
chmod 660 /dev/nvidia$i

You should make this script executed at boot time, before starting the X server.

VMware assumes its devices are already there when it starts. To solve this issue, simple put the following lines into /etc/init.d/vmware, right after the # See how we were called comment, but before the case "$1" in start statement:

for a in `seq 0 9`; do
mknod /dev/vmnet$a c 119 $a > /dev/null 2>&1
done
mknod /dev/vmmon c 10 165 > /dev/null 2>&1

If VMware wants you to run vwmare-config.pl again, just ignore it and delete the file /etc/vmware/not_configured

The easiest solution is to use the lscape package. You can then display any content in landscape format if you enclose it with \begin{lscape} and \end{lscape}:

\usepackage{lscape}
...
\begin{document}
This text is in portrait orientation.
\begin{lscape}
This text is displayed on a page in landscape orientation
\end{lscape}
...
\end{document}

Note that headings and other page-specific stuff won't be rotated. In other words, Latex makes sure that the content in landscape still fits into the layout of the rest of the document.

Just use the following settings before your \begin{document} statement:

\documentclass[a4paper,landscape]{article}
\usepackage{setspace}
\usepackage[pdftex]{geometry}
\geometry{headsep=2.0em,hscale=0.80}

There is a bug in older geometry.sty files. Just make sure you use a recent version (2002/07/08 v3.2 should do it). To upgrade, you can just replace your old geometry.sty with the new version.

The best Latex slide package I've found so far is prosper. It's very easy to use and customize to your needs and gusto. It also supports custom-made transitions between succeeding slides.