Landing at No. 8 last year, "public relations officer" was named No. 2 on the list for 2011 behind commercial pilot.
Per the website:
Stress Rank: 198
Stress Score: 47.60
Hiring Outlook Rank: 111 out of 200
Hours Per Day: 9
Public Relations Officers are responsible for creating and maintaining a positive image with the public for many companies and government agencies. They typically are responsible for giving presentations and making speeches, often in front of large crowds. This highly-competitive field and tight deadlines keep stress at high-levels for specialists. Some PR officers, also, are required to interact with potentially hostile members of the media.
See the entire list here.
By the way, the least stressful jobs list was led by audiologist, dietitian and software engineer.