[mathias_10gen]

ci( is another nifty trick that will do the same but will work anywhere between the two ('s not just at the beginning of globalConfig. See ":help text-objects" for more details on one of the more powerful feature of vim.

[thesteamboat]

You can also do cib (for inside '()') and ciB (for inside '[]') and cis (for inside sentences).

[bcrescimanno]

Gah! I'd been wondering how to do that--thanks for the tip!

[avinashv]

I very regularly do ci" or ci' to edit within strings.

[cdmwebs]

cit is another favorite. Try it inside HTML tags, for example.