With twitter I can follow people that I may be interested in following, such as other Disney lovers. But think of it as only the status window part of Facebook. The difference is, if I'm interested in what several people are doing right now, with Facebook I actually have to go to Facebook and look up each person's info. With twitter, as soon as they write something, I can see it online or have it sent directly to my cell, Blackberry, iPhone, etc.
Say you went to Disney with a group of people. If everyone wasn't going to be together the whole time, they could twitter and the other fragmented groups would know where everyone was, without having to call or direct text each person in each group. It would also be a good way to meet up with other Disney freaks in the parks. If people were twittering in the parks and I followed you, I may walk over and meet you after you tweeted that you were standing in front of Walt and Mickey at the hub at MK. Kind of like broadcasting an electronic lime green Mickey. The possibilities are endless.
There are also ways to upload a picture and then link to it easily, I just spent a weekend in Disney and twittered the whole weekend and uploaded pics in between so family and friends could see what I was doing or seeing within minutes of me doing it.
You can even hook them together so when you twitter, it also updates your Facebook status so you don't have to do both. I would follow people from the forums here for instance if I knew they were going to be in the parks the week I was there a lot quicker than I would add people from here to my Friends in Facebook.