Never thought they were cool in the first place but they are still very trendy. More than half of the people I spend my time with have at least one and most 17-27 yrs have or want one. Some are nice and impressive but I personally wouldn't do it. Permanently marking my skin isn't something I am looking for.
I got my first tattoo when I was 15 because I wanted to, not to be "cool". It's been 7 years and now I have 22.
Whoever is getting a tattoo "to be cool" shouldn't get one in the first place.