Check out Duck Duck Go; it pulls snippets from Wikipedia and other data sources right to the top of search results, which makes it easy to get the gist of what something is, without much digging: http://duckduckgo.com/?q=mail+merge
Hm, somehow the first hits look like ads - perhaps a change of fonts would be helpful? In any case, none provides the quick answer I was looking for (I already guessed it is about mergin mails). But thanks!
Plus, it's by our very own epi0Bauqu (http://news.ycombinator.com/user?id=epi0Bauqu)