In reply to goldmember:
Strengths - I'm very good at what I do, blah blah blah.
Weaknesses. I sometimes get upset with people who don't pull their weight, or sometime people say I pay too much attention to detail. (Basically all positive things spun as a weakness).
Opportunities. I think my ability to learn quickly gives me the ability to take on new challenges and my persistence allows me to see those challenges through to a positive conclusion. (You get the picture).
Threats. I haven't spent much time learning my delicate slab climbing technique (or anything else very much not related to the job). My knowledge of the 1997 version of Lotus 123 is a little rusty. etc.
Don't be honest or realistic, just tell people good things, but spun as a weakness.