Searching the bottom of the web
blog.blekko.com
blog.blekko.com
Another technique is to create a slash tag, then add results you get to it from sites you sometimes want to exclude (so for example if you are looking for Hackernews article references but don't want to include hackernews urls in the result) then you can do the search with -/yourtag and it will keep the sites that are in 'yourtag' out of your results for that query.
Can be a very powerful tool for dealing with information white-out where some high ranking site has a lot of hits.
I'll bookmark this handy page and try to get in the habit of using it regularly.