Disposable Email addresses

Disposable email addresses are email address which expire whenever you want.This basically is done to keep the spam away.As you might know that many service providers are providing email alias but most of them can be easily be filtered and hence your email id may be accessible.On the other,disposable email addresses provide you with an entirely different email address and hence saving you from spam.

Some of the service providers are:

• 33mail.com: Its a free service and provides unlimited disposable addresses,however in the free account you get limited but generous bandwidth.Once you pick up a username,for example disposable,you can create any disposable email address like ex@disposable.33mail.com whenever you want without even informing it to 33mail.These email address will be forwarded to your actual email address that you used for registering.You can cut those email address whenever you want by unsubscribing them through the link provided in  each of the forwarded emails.I personally prefer this service.It's fast and free.
  

Be Safe From short url's

You must have come across urls like http://goo.gl/XoG1z .They surely make it easier to share and remember long urls but are prone to be used by hackers.Since you so not know what site you are being redirected to beforehand this exploit can easily be used for phishing and other illegitimate uses.
In order to know beforehand the url you are opening it's better to check out to what url you are being redirected.
For url shortened by google(like the one shown before) you  can add a '+' symbol to get the info.For example to get info about http://goo.gl/XoG1z just go to http://goo.gl/XoG1z+
For all other url short urls you can visit longurl.org they decode for a number of services.You can also get their firefox addon(it works for firefox4 and firefox 5.it also works for ff6 but somehow it shows incompatible) and Chrome extension.