A couple of Firefox plug-ins help make it a bit easier to access these advanced Yahoo! search operators.

SearchStatus: to show currently active page and domain backlinks in Yahoo!

SEO for Firefox Toolbar Extension
: which will show you detailed backlink information directly in your search results

Seoquake Firefox Extension: which can be used to access Yahoo! backlink data (and a lot more) right from the search results page or from the currently active page (Seoquake),