Su.pr is a URL shortening service from StumbleUpon similar to Bit.ly or
TinyURL, and dozens of other services that let you create short url in few characters that you can share in an email, Twitter, Facebook status update, or anywhere else.
But there are somethings that Su.pr make it different from other service. First, like
Bit.ly, Su.pr also offers analytics that will give you information like how many times users have clicked on your links. And secondly, Su.pr is run by web site discovery service StumbleUpon so every time you shorten a link, you also add a web-based StumbleUpon toolbar to the link that lets users vote on the story and submit it to the StumbleUpon website. so by this you're not only getting short url with good analytics but also exposes your content to StumbleUpon's nearly
8 million users!
Beyond that it also provides personal API key like Bit.ly so you can use it in third party service. and soon you'll able to post your own urls with su.pr!!
Until, the service was only available to beta testers. But now Su.pr dropped the beta label, and Anyone can use Su.pr to shorten a link. it also integrate your Sumbalupon account. if you want to post updates directly to Twitter and Facebook using Su.pr, you'll need to enter your login info to do that.

There are many short URL service available like
tinyurl,
Bit.ly,
is.gd,
snurl.com,
tr.im,
twurl.nl and
digg.com also come up with its own short URL service and many more are coming day by day with different different features. some come up with analytic, compression, costume URL etc..& people chose the service according to their needs but Today I found a short URL service which is not having and special feature right now but things are hind in the name of the service and it definitely can be a good choice for people.
New short URL service called
Lnk.by, which is looks like simple but it also having another domains like
lstn.in (listen)
wach.it (Watch It )
seee.it (See it)
read.im (Read It) these domains says meaning like this so its a great way to create more short URLs
Like for example:
- Now you need to share a pic on Twitter so just use it see.it and your tweet goes like this: New snap from me see.it/URL.
- Now you need to post a cool YouTube video that you found so here your tweet goes like this: Found a cool YouTube video wach.it/URL.
- Now you just land on our site and now you need to share the story with your friends then your tweet goes like this: Interesting story read.im/URL.
- Now you wanna share the last.fm track with your friend so here your tweet goes like this: rocking track from cold play lstn.in/URL

So these are the innovative ways that you can use in your tweets. After all Twitter provides 140 character limit so just by choosing right URL for your tweet your saying much more in it. Of course there are
apps available where your tweets go beyond 140 limits
Right now Lnk.by is in alpha stage so there is much scope for new features and improvements. they also provides a boolmarklt for easy URL shorting.