Sweet, sweet ambiguity...
I have myself met someone in person that I met online. It's an interesting experience and can be a lot of fun, but I do not condone it without proper precautions.
I am 20 years old and rather sensible, though I suppose that is my own opinion. I spoke online with Adam for over a year before I met him and I spoke with his best friend for longer. I have also spoken with both of their parents. Both they and I have webcams so I know well what they all look like (ie: not creepy old men in disguise). When I went to visit relatives overseas a few hours from where he lived, it was too much of a chance to waste.
This was not, however, a dinner and movie meeting that places you in potentially dangerous situation with a virtual stranger. Adam came to visit bringing his family with him to meet with me and my family. We hung out as a group all day before he had to go home. It was quite awesome. He came over alone to visit us the following summer and we all had a lot of fun.
Still, there are creepy people out there so you have to be careful.