Attached Link: http://www.renderosity.com/viewed.ez?galleryid=264879&Start=55&Sectionid=0&filter_genre_id=0&Form.S

I thought of the same thing several times and even entertained the idea of modifying one of the existing ones to do what you mentioned...but I ain't no wizard at it. 3D Strike did something like this used in conjunction with a bump map (see the link) It would be great to have varying degrees of wetness though from moist droplets to streaming.