If you see these shortened URL's from Bit.ly or O.wl and you want to know if they are safe, then use these 3 websites to do just that. would also work for any length URL...FYI
Securi SiteCheck allows you to enter a URL, like the one in this article and it will crawl the website to look for any known Malware and provide you a nice report.
Google SafeBrowsing allows you to modify the end of the URL below and replace it with a URL you want to check and Google will lookup if the URL is or ever has been bad.
And F-Secure Safe Links for web sites allows you to add a plug-in to a website, it is what I use on HackerHurricane.com to validate all the URL's that I use in my Blogging.
If you are browsing using FireFox or Chrome, add the plug-in/extension called 'Web of Trust' (WOT). This little add on will show you a Re, Yellow, Green or Grey circle next to each link/URL showing you it is safe (green), warning (yellow), unsafe (red) and unknown (grey). Treat all unknowns/grey as RED since mentions in Twitter often have new URL's that have yet to make it to the unsafe database.