The Longman Dictionary of Contemporary English lists 'real' as an adverb also, but qualifies it as 'American English spoken'
Even Merriam-Webster's Online Dictionary has the following note for 'real as an adverb:
Most handbooks consider the adverb
real to be informal and more suitable
to speech than writing. Our evidence
shows these observations to be true in
the main, but real is becoming more
common in writing of an informal,
conversational style. It is used as an
intensifier only and is not
interchangeable with really except in
I, therefore, don't think it's incorrect to say something like "It is a real cool answer" in informal speech and writing! Here, 'real' is an intensifier, that is, an adverb qualifying an adjective!