I've never encountered a male Carmel and have only met a couple female ones, though I suppose that doesn't necessarily mean it couldn't be male... After all, I didn't know until a few years back that Ariel was also a male name in Jewish circles. Personally, I think I'd prefer Carmel on a girl than a guy.
*vote on my name pics at
http://www.babynames.com/Names/namelist.php and
http://www.behindthename.com/polls/search.php?searchtype=userid&terms=33210&when=all*