Here's what I do for Chrome:
- Wrench > Options > Basics > Manage Search.
- Edit the default Google Search
- Change the Keyword to something else, "g_" for instance.
- Copy the url.
- Create a new search entry with Google (Custom) as the name, "g" as the Keyword, and the url you copied.
- Add "+-site:bigresource.com" to the url.
- Save it and make it the default.
Now whenever you search using the address bar in Chrome, it will append the site exclusion so that you don't have to type it each time.
Note: This is not attached to your Google account at all and would not be applied on another computer unless it was configured there.