Yes, using the
\overfullrule command in your preamble.
This has to be set to a length (I usually set it to be ~5pt) and it prints out a black rectangle near overfull hboxes.
Here is an example (words are not meaningful, but this way they can't be hyphenated, thus creating overfull hboxes)
adfhafashfk jahsdkjash kjsahdkjashdkjhshskjdhkjhdkjdsh qwioeuqwoieuoqwiueoiw kwlqjewqejoqwiejowqiejoqwjewoqiejowqej oqwj oeijwqoie jqwoj eiwoi jeowijewjeejejeejlwkkkkkwwllwlwlwlwwlwlwlwlwlw jkljdlajkslsadj
With the fantastic result:
Sometimes it's not either advisable or useful providing a
draft option to the class, otherwise some packages (e.g.
microtype) do not work as they would in the final stages.