I do not think that it is necessary to use that here on Ask Ubuntu, as it would be very counter-intuitive to Ubuntu's helpful nature. I've been given a link with LMGTFY before in chat, and I found it rather off-putting, as it seemed like the issuer was being one of those "elitist" people who often say RTFM.
Unless the question and answer were done in a humorous light, it should probably not be used. It would be far better to share links you've found via Google than a post that just gives them a list of results, not necessarily even answers.
