Hmm, harsh but true, I've got to agree with DezG. Men hear what they want to hear, so you've got to be very up front about whether they'll ever stand a chance with you. Problem is, sometimes we're a bit flattered by the attention and - deliberately or not - can tend to keep them dangling a little longer than is strictly fair.

"You got to be cruel to be kind" or at least clear that there is no hope. Gross generalization here: most guys don't seem to grasp subtleties very well, especially when the subtle hint is at odds with their egos. Depending on your relationship, you can go about this many ways. “You’re such a good friend and since it obvious that we’ll never date (add laughter if appropriate!), I need your advise on how to get the attention of this really hot guy in my gym/coffee shop/etc.” “We work together and I never date co-workers. Ever.” “At one point I thought you were fun to hang with, but now you seem creepy – like a stalker. I don’t feel comfortable even being your friend.” DO NOT undermine your own efforts; don’t compensate for harsh words with kind gestures. You’ll just send mixed messages….