Here is some quality advice from Money Saving Expert as to how to save money whilst surfing using a MB package.
Turn off automatic updates.
This is probably the most important way to save download allowance, and the easiest way to get caught out. Many programs, as well as operating systems themselves, routinely check for available updates and download them. Downloads can run to hundreds of megabytes; not ideal if that’s all you have to play with. Turn them back on when you have the bandwidth though, or you might leave security holes open on your machine.
Turn off images when you surf.
If you’re content to do without pictures when browsing (even just temporarily) then it’s usually easy to disable them. In Internet Explorer, click Tools, then the ‘advanced’ tab, and scroll down the list to Multimedia. In that section, uncheck the ’show pictures’ box and while you’re there, the Play animations in webpages’ box. The procedure’s similar in all browsers.
If you currently manage your emails with a program like Outlook or Thunderbird (and you get a lot of unnecessary ones), you may save data by signing up to a web-based service like MS Live Hotmail, Yahoo Mail or Gmail. It should be possible to re-direct your emails there and view them without downloading, so if a friend decides to send you party pictures when you’re away in Spain, you can choose not to download them ’til you get back. .
Get rid of Ad/Spyware.
Adware and spyware programs, which usually manage to sneak onto your machine without you noticing, can use up your valuable allowance by talking to their leaders out in cyberspace. They can also leave your computer prone to attack by all manner of other nasties, so it’s worth downloading a free tool to get rid of them (on another connection if possible).