Originally Posted by FloydV
For these very such occasions can I recommend the 'noscript' addon for firefox.
Disclaimer: It will take a few days 'normal' browsing to stop it asking you for confirmation about everything but is DEFINITELY worth the time to do so
It allows you to configure, domain by domain, what sites are allowed to run any type of scripting and those which aren't. There are essentially zero threats that are in common use which can be taken advantage of in your browser with scripting playing some part (the exception being blindly clicking 'download some malware from here - click me!' links).
And aside from the security benefits (which are reason enough on their own), when combined with AdBlockPlus and Ghostery it actually speeds up your page loading times significantly because of all the resource requests which aren't performed.
Some very simple rules to using noscript:
1) Go around all your main day-to-day sites which you solidly trust and select 'permanently allow domain.com
2) NEVER click 'allow scripts globally'
3) Any page which you visit which doesn't provide you access to all the features you need (forms, voting buttons, videos etc.) - find the domain which is most likely to be hosting those features and either temporary allow (if you're unlikely/unknowingly going to visit again) or permanently allow if you're coming into regular contact with it. For example sites like facebook will require akamai's content distribution domain (akamai-hd.net I think) to work normally, so that I would add to my permanent list, but ads.doubleclick.net I would not even do temporary unless the site didn't work without it.
4) For the occasion when you're in a rush and just 'want a site to work' then choose 'Temporarily
allow all this page' and it will work until you close firefox.
That should keep you plenty safe enough from 99% of web threats, for the really paranoid there's the lynx text browser in a linux vm running from a live-cd on ESXi virtualised hardware - aka the dark ages.