Adblock Plus

I'm trying to block entire websites - can I use this app to achieve this?
Custom filter does not seen to work (or I'm doing it wrong)
Have tried
http://www.example.com
http://www.example.com*
http://www.example.com/*

Appreciate your thoughts
TIA

you can block the content (images, scripts, other external sources) but you still can type the address in the url bar and land into the site (even with all content blocked by the filter)

you need something else like
http://www.pimpmysafari.com/items/Waste ... your-time/

or add the site to the hosts file
http://www.tekrevue.com/tip/edit-hosts-file-mac-os-x/