theContratian sez: "This thread has really gone all pear-shaped."

Adj. Out of shape, unorganised, wrong. Heard in the expression go pear-shaped. E.g."All our plans went pear-shaped after our funds were cut by the finance department."

http://www.peevish.co.uk/slang/p.htm

It’s mainly a British expression. “It’s all gone pear-shaped”, one might say with head-shaking ruefulness, in reference to an activity or project that has gone badly awry or out of control.

http://www.worldwidewords.org/qa/qa-pea2.htm

If something has gone pear shaped it means it has become a disaster. It might be preparing a dinner party or arranging a meeting, any of these things can go completely pear shaped.

http://www.quad4x.net/yojinbo/slang.html

adj. If something has gone pear-shaped it means it's all gone rather wrong. Usually it's meant in a rather jovial sense, in a similar way to the American expression "out of kilter" or "off kilter". You might see it in contexts like "Well, I was supposed to have a civilised dinner with my mates but we had a few drinks and it all went a bit pear-shaped". You would not see it in contexts like "Well, she went in for the operation but the transplant organ's been rejected and the doctor says it's all gone a bit pear-shaped".

http://english2american.com/dictionary/cat_misc.html

"It went pear-shaped" is used in modern English to signify a comedic fiasco or similar disaster. In almost every circumstance, it refers to an undertaking or project that resulted in failure, but caused no grievous harm to anyone involved. Further, it provides a gentle suggestion that the fiasco was a result of nature and beyond the control of any specific individual. It is not regarded as vulgar or offensive. Despite its common usage, the origin of the phrase remains obscure.

http://alt-usage-english.org/ucle/ucle9.html

3. colloq. (chiefly Brit., orig. R.A.F. slang). to go (also turn) pear-shaped: to go (badly) wrong, to go awry.

http://www.oed.com/bbcwordhunt/pear-shaped.html

I've also heard it used (approvingly) of some young women's figures.

Bingley

used (approvingly) of some young women's figures

Or the tones produced by a good singer.

I've also heard it used (approvingly) of some young women's figures.

You must be thinking of the bottom half of an hour glass figure, Bingley. :)

It strikes me as odd that an expression would be used in both negative and positive ways -- what with pear-shaped figures and pear-shaped tones being good and pear-shaped other things being bad.

pear-shaped figures ... being good

In ordinary parlance, a "pear-shaped figure" is not "good", Father Steve. [But it is not necessarily a pejorative either. It is simply a description of a particular body type.]

Let's look at a few female 'body models' of our times;
In the 50's we had Marilyn, with a voluptuous hourglass figure 37-23-36. Next came Twiggy, who was the exact opposite, with vital stats of, 32-22-32. The 80's bought us Cindy Crawford, and the 90's Kate Moss 33-23-35.
----------------
Finding the pear-fect fit

If you have a pear shaped figure don't be alarmed. Although the styles of the clothing on the UK high street would suggest otherwise, you are actually in the majority, and all you have to really worry about is balancing the top half with the lower half of your body. Easier said than done given the choice on the high street? Let me enlighten you...

http://www.uniquelywoman.co.uk/
women's_pear_shaped_figure_clothing.htm

There is also a discussion here about "vanity sizing" [which is new to me].

P.S. Snipurl.com isn't up today so I separated the url into 2 lines.

Fr. Steve, you missed out on one link:
http://wordsmith.org/board/showflat.pl?Cat=&Board=words&Number=4879

Reading that thread, and noting the names -- some strange, some familiar -- was like a walk down Memory Lane, which, for me, at times, is a deserted street.

Good god, but I've been around here a long time. How did that happen?

Ann has been here since 5 January 2001 (the Eve of the Feast of the Epiphany). I have been here since 6 September 2000 (the Feast of Saint Magnus of Füssen). The boo boo occurred because I am too stupid to look things up through the search function ... but someone is always kind enough to point that out.

I don't think I'll ever use pear-shaped to describe a woman in a positive sense, it doesn't seem flattering to have the semblance of a pear if you ask me (big butt, small breast? that's the image I'm getting).

And yet some descriptions in the Arabian Nights work out to just that - women with heavy thighs, large hips, narrow waists and small breasts. The women these decriptions apply to are clearly considered beautiful.

Welcome aboard, Logwood.

If I ever used "pear shaped" to describe my sweet bride, I'd need both my long-term care and my disability insurance.

Regarding the term being both a complimentary and derisive so are most adjectives. When I am buying a chicken to roast I look for a nice plump one (although pear shaped might be more accurate) but I wouldn't describe a friend that way. Nor would I tell a body builder that he was looking nice and slim but I'd be pleased to hear it from him.