there is a guy at work who is interested in me, but i'm only looking for friendship too. he has taken me out to dinner and stuff also. the way i 'dropped the hint' to him was by saying how happy i was being single, etc, and just being fun and matey and stuff. he got the memo pretty quickly.

i dont think you need to make it into a big deal, just drop it into conversation casually. e.g., for me it flowed easily, because we were talking about exes and so i had the opportunity to go "i'm so glad i'm unattached now... wouldn't trade this for the world" etc. i made sure to keep up contact with him afterwards though, so he knew i still wanted to be his friend. we've got it good now.