URL shortening services - is it safe to use?

You probably noticed the increased use of URL shortening sites such as TinyURL, Bit.Ly, ShortURL, and the new goo.gl. Such services helps writers in blogs and twitter to list urls as a short word, the listed word does not show the real url but clicking on the short url will take you to the actual web site.

Is it safe to use and what are the dangers behind it? 

Some of the risks include:

• We don't know where the link is taking us.
• The real site could be a malware hosting site, which could be mapped to a popular and known site.
• Such urls could be used for a phishing attack.

So how do you protect yourself? 

Use online services such as LongURL or  Expandmyurl. If Firefox is your browser,  add this add-on, which uses  the LongURL online url expansion service to verify. Above all, try not to use such services.