Question: Recently there has been a lot of hype about URL Shortening. I guess some URL Shortening services even offer tracking stats. But, doesn't adding one more level of look-up to the original URL affect page ranking in any way? Just curious to know.

Answer: 
Well, I can tell you one thing that *won't* affect your PageRank - URL shorteners using DNS.

The vast majority of URL shorteners use clientside redirection - either via scripting/meta-refresh, or via frames. Those might affect your ranking as they change what Google sees - you never know. Examples are anything from [Dot.tk](http://dot.tk) to [PopNIC](http://www.popnic.com/), [Smartdots](http://smartdots.com), [JoyNIC](http://www.joynic.com/), [HomeNIC](http://www.homenic.com/), [EuropNIC](http://www.europnic.com), [Tipdots](http://www.tipdots.com), [DuoNIC](http://duonic.com), [UnoNIC](http://www.unonic.com/), [Cydots](http://www.cydots.com/), [FreeNIC](http://freenic.at), [Mediadots](http://mediadots.com), [Ulimit](http://ulimit.com), [kurzURL](http://kurzurl.de), [co.nr](http://co.nr) and [de.be](http://nic.de.be)/[de.vu](http://nic.de.vu)/[ch.vu](http://nic.ch.vu).

A few services are using proper DNS for forwarding, though. Those include [Afraid.org](http://afraid.org), [co.cc](http://www.co.cc/), [No-ip](http://no-ip.com) and [Da.ru](http://da.ru). This is fully transparent to visitors and spiders, so you can be sure it doesn't affect your rank.
No it does not affect page ranking. But the url should not link to a bad neighbour hood like porn, viagara etc. URL shortening is mean to shorten and place it instead of placing huge url. You can try [zxc9.com](http://zxc9.com) and also its API for your services.