Do you like web 2.0 style? Do you like tags and tag clouds? Would you like to see tags on every site you browse?
Tags Everywhere Firefox Extension does exactly this and even more.
Extension shows related Del.icio.us tags on top of plain sites.
In some cases extension shows related tags clouds below every item of sites list of some popular search engines (Google, Yahoo, MSN-Live.com) and web2.0 news (Digg and Reddit).