What is is.gd?
      is.gd is a service that shortens URLs such as web addresses. This is useful in many circumstances (see below) e.g. in email clients that break long URLs.

For example, you can turn
            http://maps.google.co.uk/maps?f=q&hl=en&geocode
            =&q=louth&ie=UTF8&z=12&iwloc=addr&om=1
into : -
            http://is.gd/1

Our goal is to allow shortening URLs to the maximum extent technically possible.

Uses for is.gd
Here are just a few of the many uses for is.gd's URL shortening service: -

    Shorten web addresses for emails, forum posts, blogs etc. which cannot handle long URLs and might wrap them, making them unclickable
    Lower the character count when texting web addresses to a mobile phone
    Hide the real URLs of affiliate links from visitors to your site
    Obscure your real email address from bots which harvest them to spam (enter an address like mailto:myaddress@myisp.com)
    Circumvent protections on sites which don't allow direct links to a competitor's site (if you are violating a site's terms you do so at your own risk)
    Clean up bookmarks for social bookmarking sites or sites with low character limits like Twitter
    If you dislike a website and have to mention it (e.g. when complaining about it), link via is.gd so that your link does not help the site's search engine positioning

Certain uses of is.gd are forbidden, for example use in unsolicited commercial email (SPAM). Be sure to check our terms of use

        或许使用者对于缩短网址并不陌生，如最常用的tinyurl ，就是缩短网址的龙头。但或许您会觉得网址还不够短、不够好记、不够有特色，那么您不妨试试使用is.gd 来缩短您的网址。is.gd不仅能够让您的网址缩的更短，还具备隐藏原网址的功能。
        is.gd 在使用者填入原网址后，按下Compress That Address! 就会将网址改写为is.gd/xxx 格式，这个xxx将按照顺序随机产生，使用者无法自行挑选。


Your new shortened URL is:
http://is.gd/MbE   (if you have Flash enabled it is automatically copied to the clipboard, otherwise use control+c or right click/copy)

Your is.gd shortened URL is http://is.gd/MbE[open in new window] (16 characters).
The original URL was http://lulizhu.za.net[open in new window] (19 characters).

We made your URL 16% (3 characters) shorter!

   有62个短网址将会有 - 1字元的/xxx
   从62 - 3,844个短网址将会有 - 2字元的/xxx
   从3,844 - 238,328个短网址将会有 - 3字元的/xxx
   从238,328 - 14,776,336个短网址将会有 - 4字元的/xxx
   从14,776,336 - 916,132,832个短网址将会有 - 5字元的/xxx
   从916,132,832个短网址将会有 - 6字元的/xxx

网站网址：http://is.gd
演示网址：http://is.gd/MbE

注：本文转自典藏秘籍堂
    is.gd后面的字母组合区分大小写！！本人刚刚测试！