The blockquote displays in standards-compliant browsers with the “big quotes before” effect, and in IE with a thick left border and a light grey background.
Unlike other blockquote techniques, this style does not require a nested block-level element (like p). As such, it turns a paragraph into an inline-styled element to keep the content from dropping below the quote.

blockquote {
  background:#f9f9f9;
  border-left:10px solid #ccc;
  margin:1.5em 10px;
  padding:.5em 10px;
  quotes:"\201C""\201D""\2018""\2019";
}
blockquote:before {
  color:#ccc;
  content:open-quote;
  font-size:4em;
  line-height:.1em;
  margin-right:.25em;
  vertical-align:-.4em;
}
blockquote p {
  display:inline;
}

Example

Pellentesque habitant morbi tristique senectus et netus et malesuada fames ac turpis egestas. Vestibulum tortor quam, feugiat vitae, ultricies eget, tempor sit amet, ante. Donec eu libero sit amet quam egestas semper. Aenean ultricies mi vitae est. Mauris placerat eleifend leo.