When you paste a URL in the FB share, FB pulls out some information about the URL along with any available images.
I created a similar feature in ASP.NET few years ago and I got the project file while clearing out one of my disk partitions and thought of sharing it.
This project uses HTMLAgilitPack (http://htmlagilitypack.codeplex.com/) and XPATH for processing the HTML.
A working preview.
You can download the code here (http://sdrv.ms/MM5zA1) from SkyDrive.
You might have noticed that recently FB added a new feature in the chat to show whether the other party you are chatting with have seen the messages you send or not. This is a cool feature for some extent as long as I can check whether my friends have seen the message I send. But same theory applies to me as well. I personally do not like this much.
There are plenty of other ways to avoid a person in FB. Simply I can make myself offline to that particular person. But let’s discuss about something really wobbly about this feature.
Technically speaking this seen feature can be implemented in many ways. And also a real question I have in my mind is ( and FB did it in a very sneaky way) to know whether FB assures that the other person read it or not. The answer is No.
I tested few scenarios of this ‘seen’ feature.
The rule of thumb is, FB detects the seen when and only if your browser tab on which FB is loaded and the chat window of a particular chat are open and in focus.
Simple.
And FB says whether the user has seen the message or not. It doesn’t say anything about whether the user has read the message. Because FB sends the seen acknowledgement to the other party approximately after 8 – 9 seconds from the time it got the focus event fired. In some cases this time is very short; something between 1 – 3 seconds. But it doesn’t bother about the length of the message whether the message can be read in 10 seconds or not. So it just says the users has simply seen the message. It makes perfect sense.
In Windows 7 we can hover the taskbar icons and get the full snap of the windows we have opened. From the OS perspective this is not focus. This applies to FB as well. Because technically in FB this feature works on Javascript focus events which get the focus signal from the browser, where the browser get the triggers from some sort of a system call from the OS.
So you can use this method to read the messages without getting caught. 🙂 but this is not always possible and easy.
The greatest social networking giant with more than 500 million users. Wow 500 million what a great number. We can see almost all the businesses having their pages or ads or something in FB; from Microsoft to the Dosa Shop near my campus. 🙂
I thought about some features that FB may implement in the future, and some features which I consider as nice to have.
FB can give some themes to decorate the home page as we want. These can be pre defined themes as Windows Live provides or they provide an editable CSS as MySpace does. I read in a blog entry this feature is not implemented because FB wants to ensure the same loading time in all the pages and no more delayed loading. But whatever it is it would be nice to have themes as we want.
Another advanced feature and I name this as ‘Facebook Globe’ which would be a prototyping tool to visually maps the relation ships we have and the links and the data shared. In highly advance this can also maps photos and able to create panoramic photos. Wow that will be really great and sounds interesting. Do not steal this project idea.
Just wanna share some thoughts on Facebook. Put your own suggestions and ideas that FB can adopt in the future.
Social networks like Facebook and Twitter use a method of authentication known as OAuth to grant permissions to the applications to deal with our data. The permission grant is explicit. But we do not know what the permission we are giving to the application. Though the social networks boast lot about this OAuth as secured and more, really they are not much secured.
It similar to give your password and username to this applications
Let’s see that if you are supposed to take a quiz in the Facebook. You click on the application and you will see a similar dialog box as below.
What we do in the curious of taking the quiz (even though we are not we do not read it 
). We just click the ‘Allow’ and jumped into the quiz or that particular app and do the stuff, publish the result in the wall (mostly) and exits. We do not care about the evil side of this.
Now take a close at the above declaration
Now you can understand it is similar to giving your password to someone. The worst part we think that this permission grant is for those few minutes we use the application. But once you give the permission it will remain forever until you remove the permission. Yes you can remove the permission.
In Facebook Go to the Account –> Application Settings.
There you can see the list of applications authorized by you, in the Authorized category. Simply click the ‘x’ mark to remove the authorization. When I checked my list there were 354 applications that I have authorized. Sad part is most of them are mere quizzes that we only take once. But they still have the access to our data. 
Creating your own app in Facebook using the OAuth is easy and you can get more details on the following page. http://developers.facebook.com/docs/guides/web
More on Facebook OAuth 2.0 : http://developers.facebook.com/docs/authentication/
Facebook OAuth 2.0 has some extended privilege options as well which gives full permission to our data.
Some applications and quizzes are more tempting so do them and delete the permission after you have done 
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