You know those URL shortening services like tinyurl.com, is.gd and bit.ly? Here is an example: http://twurl.nl/jvuncl. Looks like a pretty normal shortened URL, right? Now eat this:
~/tmp$ wget http://twurl.nl/jvuncl
--13:56:22-- http://twurl.nl/jvuncl
=> `jvuncl'
Resolving twurl.nl... 87.255.53.196
Connecting to twurl.nl|87.255.53.196|:80... connected.
HTTP request sent, awaiting response... 303 See Other
Location: http://bit.ly/v9B9T [following]
--13:56:22-- http://bit.ly/v9B9T
=> `v9B9T'
Resolving bit.ly... 128.121.254.205, 168.143.174.25, 128.121.254.129, ...
Connecting to bit.ly|128.121.254.205|:80... connected.
HTTP request sent, awaiting response... 301 Moved Permanently
Location: http://www.socuteurl.com/mistergoosey [following]
--13:56:23-- http://www.socuteurl.com/mistergoosey
=> `mistergoosey'
Resolving www.socuteurl.com... 64.62.158.120
Connecting to www.socuteurl.com|64.62.158.120|:80... connected.
HTTP request sent, awaiting response... 302 Found
Location: http://tinyurl.com/o7r5b6 [following]
--13:56:23-- http://tinyurl.com/o7r5b6
=> `o7r5b6'
Resolving tinyurl.com... 195.66.135.131, 195.66.135.140
Connecting to tinyurl.com|195.66.135.131|:80... connected.
HTTP request sent, awaiting response... 301 Moved Permanently
Location: http://is.gd/qGeL [following]
--13:56:23-- http://is.gd/qGeL
=> `qGeL'
Resolving is.gd... 78.31.109.147
Connecting to is.gd|78.31.109.147|:80... connected.
HTTP request sent, awaiting response... 301 Moved Permanently
Location: http://www.boingboing.net/2009/04/04/why-url-shorteners-s.html [following]
--13:56:23-- http://www.boingboing.net/2009/04/04/why-url-shorteners-s.html
=> `why-url-shorteners-s.html'
Resolving www.boingboing.net... 204.11.50.136
Connecting to www.boingboing.net|204.11.50.136|:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: unspecified [text/html]
[ <=> ] 147,917 111.42K/s
13:56:25 (111.08 KB/s) - `why-url-shorteners-s.html' saved [147917]
Whoa that was fun!
...
Now back to work.