I've met a couple of people individually and also attended a group event several times. I love chatting with people online, but meeting in person adds a whole new dimension. Having a chance to talk, pat someone's diaper butt (with permission), and just "be Little" in person is pretty awesome.
I met the first Little at his house. We chatted for quite a while online, and I was apprehensive to meet him at his home, but I did and it turned out OK. Really nice guy who I now play daddy to. In hindsight, I would have felt more comfortable meeting somewhere in public first.
I met another DL online, then we met for lunch and talked for a couple of hours. Super nice guy, and we're already working on plans to meet up at his place soon. Having met and talked, I have no concerns meeting him at his place.
I'm meeting a third person in the next few weeks. The DL I mentioned above has already met him, so I'm pretty comfortable meeting up at his place. Looking forward to that, too!
Then, I've attended a local Littles club event, where about 25 or 30 guys and gals were diapered and socializing, playing, eating, cuddling, and just hanging out. That was (and continues to be) soooo much fun! I've met people there who I will certainly be meeting again one-on-one for playtime. This was where I exposed my Little self to another human for the first time (other than my wife)! It was pretty scary walking out in a diaper and onesie for that first time. Now, though, after attending 3 or 4 times, it's no big deal, and I can't wait for the next meetup!
So, at least for me, meeting people in person adds greatly to the fun. I'll continue to (carefully) meet up with others as the opportunity arises. If you're very careful, and take baby steps in meeting others, I would really encourage it. BUT, you do have to be careful, of course. Not everyone has good intentions, and some may have different ideas of what is "fun".