How to preview or check where a shortened link will bring me to?

Vital knowledge for anyone who is suspicious of any shortened URL links (that might bring them to virus/malware-infected, phishing or shady sites).

For bitly links

Simply add a + sign to the end of any shortlink in your browser. For example, for http://bit.ly/Wn2Xdz just enter http://bit.ly/Wn2Xdz+ into your browser and you'll be sent to a preview page for the link. Once you've decided that it's safe to visit that site, then you can go ahead and click that link. 

Source: http://support.bitly.com/knowledgebase/articles/76775-how-can-i-be-sure-a-bitly-link-is-safe-to-click-on

-----------------Note: The following parts are taken from the link below. Enjoy!----------------------

Link: http://security.thejoshmeister.com/2009/04/how-to-preview-shortened-urls-tinyurl.html

For TinyURL links

Add "preview." before the "tinyurl.com" portion of the URL to see where the link will take you. For example, change http://tinyurl.com/cz23u4 into http://preview.tinyurl.com/cz23u4 to get the preview

Better yet, you can force TinyURL to always take you to the preview link whenever you click on a tinyurl.com shortcut. If you go to http://tinyurl.com/preview.php you can set a cookie for the site that will enable this feature.

For goo.gl links

Google's short URLs can be previewed the same way as bit.ly URLs. Just add a plus ("+") after a goo.gl URL to see where the link will take you, and also to get statistics for that shortened URL. For example, you can change http://goo.gl/1tRbb into http://goo.gl/1tRbb+ which will redirect to http://goo.gl/info/1tRbb

Alternatively, you can add "/info" after the "goo.gl" portion of the URL. For example, you can change http://goo.gl/1tRbb into http://goo.gl/info/1tRbb

For is.gd links

Just add a hyphen ("-") to the end of any is.gd URL to preview it, e.g. http://is.gd/rZ7U can be changed into http://is.gd/rZ7U-

For Snipurl / Snipr / Snurl / Sn.im / Cl.lk links

Add "peek." before the snipurl.com, snipr.com, snurl.com, sn.im, or cl.lk part of an address to find out where the link leads, e.g. http://snipurl.com/fpyfq can be changed into http://peek.snipurl.com/fpyfq

For Tiny.cc links

Just add a tilde ("~") to the end of any tiny.cc URL to preview it and get statistics for it, e.g. http://tiny.cc/d7bza can be changed into http://tiny.cc/d7bza~

For BudURL links

Simply add a question mark ("?") to the end of any BudURL shortcut to preview it, e.g. you can change http://budurl.com/gtg3 into http://budurl.com/gtg3?

For Fwd4.Me links

Like BudURL, just add a question mark ("?") to the end of any Fwd4.Me URL to preview it, e.g. you can change http://fwd4.me/uPV into http://fwd4.me/uPV? (Note: You need to enable JavaScript in order to create Fwd4.Me URLs.)

For su.pr links

StumbleUpon's URL shortener, su.pr, can be previewed similarly to bit.ly; just add a "+" after a su.pr URL to get a preview page, e.g. you can change http://su.pr/2xZo8c into http://su.pr/2xZo8c+ (Note that su.pr shortcuts put an annoying StumbleUpon bar across the top of the destination page.)

For yi.tl links

This service provides a preview if you add a tilde ("~") after the URL. For example, you can change http://yi.tl/B03ImN into http://yi.tl/B03ImN~ to see the long URL. As a bonus, you'll also get to see the title of the destination page and see whether the URL is in Google's phishing or malware database.

For y.ahoo.it links

In order to preview y.ahoo.it URLs, you must go to http://y.ahoo.it (with JavaScript and cookies enabled) and click on the checkbox next to "Show me a preview of the destination URL when viewing y.ahoo.it links".

For sURL.co.uk links

When you visit a sURL.co.uk short URL, you will automatically get a preview of the destination address and its status on hpHosts, Malware Domain List, and PhishTank so you can instantly see whether it's a known malware or phishing scam site. The preview cannot be disabled. This is by far the most safety-focused URL shortening service, which is no surprise since it's operated by the maintainer of hpHosts.

For cli.gs links

Another service that automatically gives you a preview is cli.gs. The feature can be explicitly disabled by each user, if desired; there's a "Click here to disable previews" link on each preview page, which when clicked sets a cookie to disable previews in the future.

For Tinyarro.ws / ta.gd links

Tinyarro.ws is the only other URL shortener service I know of that automatically gives you a preview. Again, the preview can be disabled, if desired; there's a "Never show a URL preview again" link on each preview page, which when clicked sets a cookie to disable previews in the future.

Other services

Unfortunately, several popular services (including, as far as I can tell: t.co, twurl.nl, moourl.com, ow.ly, lnkd.in, lnk.ms, wp.me, mcaf.ee, and awe.sm) don't offer the ability to preview the original long URL before visiting it. However, if someone else sends you a shortened link from another service and you want to preview it, you may still be able to do so using a third-party site. Here are a couple of sites that let you do just that:

To unshorten a shortened link

Online sites

Toolsvoid Unshorten URL - Works with almost any site

LongURL Expand URL - Works with hundreds of popular sites. 

Browser Extensions (For Chrome and Firefox only)

Unshorten it

Source: http://security.thejoshmeister.com/2009/04/how-to-preview-shortened-urls-tinyurl.html