I use cryptic clues in mine. For example, 1FemCous + #
[lolcat] would be name of first female cousin with the name capitalised followed by the first 6 hex digits of the MD5 Hash of lolcat
.
Anyway, that's a side thing. I think Microsoft / MSN provide default security questions when registering, however if you go into your options / settings / etc (I don't really use their web stuff anymore) then you can customise it here.