Hmm...19 guys...probably don't need a ton of space...I would think any local neighborhood park would do.
If you're traveling, several of these guys are used to living in style, I would recommend the Park Plaza hotel, or the Park Hyatt (my favorite is the one in Sydney on the harbor).
If you're in Pittsburgh, they might enjoy the coffee at Eat N Park.
If they have any interest in science and technology, a tour of Menlo Park might be fun.