yahoo mail provides a service Yahoo! AddressGuard, to create and use many of the free Disposable email. it's not fake email kind of thing. you can actually use the same email address for receiving the mails.

How to create?

Go to Mail options -> Spam -> Set up a disposable
or in Yahoo Mail Classic Options -> Mail -> AddressGuard

format: Basename-keyword@yahoo.com

The Basename is the unique ID other different from your Yahoo ID. which should be available for you to use. Basename will be the same in all of your disposable email address which you will create.
keyword will be differ for every new disposable mail address. For instance, if you are creating an address to receive an email newsletter from Widget Designs, your keyword could be "widget" or "widgetdesigns". and then you can set the folder where those mail should be delivered. you can also send mails using this new mail address by checking on "Allow messages to be sent from this address".

when ever you start getting spam through any of your disposable addresses, just delete the address. and can say bye to spam.

How it is more meaning full then using gmail plus sign for filtering spam?

in gmail you have to use your running gmail id and then you concatenate a new keyword with "+" sign. the spammers can split up it easily and can use your running gmail address easily. but in case of yahoo disposable mail address, they can not remove the remaining word after "-" in your mail address. they have to use it full. otherwise you can't receive the mail. so it is much meaning full.

Related:

• Gmail: how to use 'plus' sign for filtering mails
• Three Ways to Use Gmail on your Phone
• send secure encrypted email message
• Email zip file without signing in your email account

by: The 'Plus' Side of Gmail
you can use 'plus'(+) sign for filtering the mails in your gmail account. Like many other Email providers, Gmail supports the standard "plus" addressing scheme. But just what is it, and how can it help me?

The "plus" method of addressing lets you add additional words to your account name (the "left side" of your email address.) For example, if your email address is "amitshahc@gmail.com", you could add "+office" when you give your email address to members of a club to which you belong. So, your email address would now be "amitshahc+office@gmail.com". But why would you want to do this? Think of the "plus" word as an extra "keyword" or "tag" that you can use to better manage your messages.

Using this example, say you email an invitation to your colleagues in a office asking them to rsvp to the invitaion. You ask them to reply to "amitshahc+nope@gmail.com" when sending you a response, if they don't want to come. and reply to "amitshahc+ofcourse@gmail.com". Assuming they follow your directions, You can then set up a Gmail Filters to automatically route emails to specific Labels based on the addresses. It's a simple example, but the uses can be numerous.

Another use is when you are shopping online. When asked for an email address, use something like "amitshahc+amazon@gmail.com". That way, whenever you get future emails addressed to that address, you'll know that it's either from Amazon directly or from someone to whom they sold your email address. This can be a somewhat effctive way to track spam. Just be aware that not all email systems recognize or accept "plus" addresses. In fact, some spammers even strip it out completely, but it's a cool tool, none the less. The best way is to just try it and see if it works for your application!

Related:

• send formatted invitation by Gmail
• filter spam mails using free Disposable Email by Yahoo

This is an add on for firefox and unbelievable but true, it's also available for Internet Explorer (IE) as a toolbar. it shows the image previews of the web pages of search results you are searching with Google search. it's not official Google offering like Google Toolbar.

To disable GooglePreview click on in the status bar (bottom right corner) -> click again to enable.

If you only see gray borders next to the search results, you may have the 'Redirect Remover' extension installed. In this case please add 'googlepreview.com' to white list of 'Redirect Remover'.

Download plug-in: Firefox & IE

Related:

• Save opened tabs in IE-7: Session Manager
• View any Picture Album as 3D WALL
• Save last open tabs in Firefox
• Download all from the webpage

PicLens is the plug-in (add-on) which transform your browser into a full screen 3D wall. it's a cinematic presentation on which you can drag that wall, click on the photo to get focus on and will come ahead in it's original size, zoom in and out the wall to see the complete gallary. belive me it's an amazing experiance to use the add-on.
PicLens is free to download, free to use, and does not contain any adware or spyware whatsoever.

Features:

• Enjoy photos in full-screen mode
• Quickly drag, click, and zoom in a "3D Wall" interface
• Search for web images within PicLens
• Play a slideshow of image search results and photo albums
• Fly through 1000s of images in a split second
• Search in multiple languages
• Jump from PicLens to the corresponding webpage
• Sit back and explore photos with your Apple® remote

Browsers Support

Piclens currently supports
Safari, Internet Explorer, Firefox

One of Google's many features is the calculator. It can solve not only basic math questions, but also more complex mathematical functions.

Steps

1. Go to Google
2. In the search box, type your problem. ex. 10*5(3-sqrt25) which is 10 times 5 times 3 minus the square root of 25.
3. Google will do the rest.
4. Google's calculator can also convert between a remarkable number of units. You can do compound operations, too. Try typing in one of the following:
   • 3 tablespoons in teaspoons
   • 12 mph in furlongs/fortnight
   • 16C in F
   • 7N/16m^2 in Pa

Tips

• Common symbols used by the calculator are:
  • Add: +
  • Subtract: -
  • Multiply: *
  • Divide: /
  • Exponent (raise to the power of): ^
  • Square root: sqrt(number)

source: http://www.wikihow.com/Use-the-Google-Calculator