I understand the theory behind child selectors (http://reference.sitepoint.com/css/childselector) but anybody give an example of when they regularly use it because it is the best solution? I’m having trouble thinking of one.
The page you linked to gives a nice example. ul > li selects only the LIs that are direct kids of the UL, leaving the LIs of the OL alone. The only other way to select just the UL LIs would be to put a class on those, which is less efficient.
The child selector is used a lot in drop downs where the first level is usually styled differently from the elements in the drop down.
In most cases the same effect can be done without the child selector by cancelling out the styles on the nested element but requires more code or the addition of a class.
I very rarely use the child selector because IE6 doesn’t support it and the workarounds are pretty straight forward anyway.