PDFs ranking?

Have PDFs commonly shown up in SERPS

[SuperSport]

While researching one of my popular 2 word kw phrases, I noted that now the 5th spot is taken up by a link to a PDF. How does this happen?

The link goes directly to the PDF, not an HTML page with info (or KWs, meta info, or H1 tages for that matter).

Can and does the Google bot recognize PDF text?

[takagi]

Yes, Google can read the PDF files and even follow links in it. See also Google's FAQ File Types [google.com] page.

[piskie]

SuperSport
In addition to returning pdf's in normal SERPS, Google allows a searcher to return "ONLY" pdf's when using advanced search.

[g1smd]

Google does not respider PDF content very often. I think they tend to think of it as static information.

I know of a site that had some information that was updated about 4 months ago. The site has both HTML and PDF versions of the information. Both were updated on the site the very same day. However, for Google results, the HTML version has updated in the SERPs many months ago, but the PDF version in the SERPs still comes up for the old search terms and the cache still has the old copy.

Google can also see inside Microsoft Word Docs and Rich Text Format stuff, as well as a few others.