Unfortunately, I've found articles on this site to be poorly articulated opinion pieces, written from broken premises and with incorrect information, rather than actual UX practice documentation. Comments that disagree and point out errors are routinely deleted; a response to the one comment of mine that has remained live included the line, "this is a blog, not a science lab." One of the differentiators of UX from art is that it can be tested, so I find the author's attitude professionally disappointing.

LukeW's seminal book, "Web Form Design" has an entire chapter (19 pages!) about label placement. Some notes:

This paper is cited as discussing a major eBay form design, explaining their methodology: http://scholar.google.com/scholar?cluster=106605571117736457...

This article is cited as having done the eye-tracking research for label placement: http://www.uxmatters.com/mt/archives/2006/07/label-placement...

The chapter starts out with the note that "it depends" for your specific usage.

A summary of the results are available on his blog: http://www.lukew.com/ff/entry.asp?504

He also discusses using inline labels on his blog: http://www.lukew.com/ff/entry.asp?687