As a recent wearer of compression tights ive wondered if it's a posers game or if they really like.....if you lok hard for the science however, it seems they work ! Here's a quote from Peak Performance Online which actually provides a nice summary of the research
"Too often modern athletic clothing is worn simply as a fashion garment. However, for those individuals involved in intense and/or competitive activity, the literature would suggest that compression clothing may provide both a performance and a recovery aid. The mechanisms that mediate any performance gains appear to be related to a considerable number of variables including enhanced proprioception, reduced muscle oscillation, enhanced lactate removal and/or psychological factors (ie subjects like the feel of the garments and perceive that they can improve performance)."