On the receiving machine (booted from live CD or similarly inactive partition sda):
netcat -l -p 4778 | dd of=/dev/sda

On the sending machine (booted from live CD or similarly inactive partition sdb):
dd if=/dev/sdb | netcat 192.168.0.4 4778

(-l listen; -p port)

To add a permanent static route to a system with one NIC, you need to edit the
/etc/network/interfaces file:

The following section needs to be replaced:

# The primary network interface
auto eth0
#iface eth0 inet dhcp

Modify as follows:

# The primary network interface
auto eth0
iface eth0 inet dhcp
up route add -net 10.8.0.0 netmask 255.255.255.0 gw 192.168.0.3
down route del -net 10.8.0.0 netmask 255.255.255.0 gw 192.168.0.3

If the jpg image doesn't have exif header you need to create it first:
jhead -mkexif
Then enter the time stamp data:
jhead -ts2009:08:15-10:30:00

There are dozens of methods how to join PDF files. Here is one of them:
gs -dBATCH -dNOPAUSE -q -sDEVICE=pdfwrite -sOutputFile=joined.pdf sample1.pdf sample2.pdf

To determine the file type of the file "sample.txt" you just type:
file sample.txt
Usually it'll tell you only that it is a text file. To get to know more about the encoding type:
enca -L none sample.text
The -L switch tells the program what language is used in the file. If you don't know, just use none.
To convert the encoding from ISO-8859-1 (latin1) to UTF-8:
iconv --from-code=ISO-8859-1 --to-code=UTF-8 sample_iso8859-1.txt > sample_utf-8.txt