I have one kid who's a darter. He's four now, so he's a little better than he was when he was two or three, but still, visits to crowded museums and outdoor concerts cause me a certain amount of anxiety. My most recent terrifying episode was at a crowded park, where I saw him go into the monkey bars area, then I turned to say something to my other kid, then turned back, and... he was gone.
It was like a movie where the POV is a wild swinging of the camera back and forth: Playing kids, the tinkling ice-cream truck and -- no sign of my son. My older kid and I fanned out, and eventually I spotted him at the other end of the park, playing happily in the dirt. For a moment, I had renewed sympathy for those parents whose kid fell in the gorilla cage.
Now I keep a closer eye on him, but I've also come across a few good tips for keeping track of your kid in a crowded place.
Snap a Picture
Sometimes it's easier to scan for bright clothes than for one brown-haired kid, but this doesn't work if you can't remember what they're wearing. Now I take a picture of my kids if we're going to be anywhere crowded or chaotic, so I can remind myself of what they're wearing, or God forbid, describe them to the police.
Keep Yourself in Their Sight
I used to say, "Stay where I can see you!" but then I realised they have no idea what I can see. Now I say, "Stay where you can see me," which means they (usually) don't go around corners or dart down hallways.
Set a Meeting Place
Anyone who was a child before mobile phones will remember this strategy: Make an "if we get separated" plan. At my kids' favourite museum, they know to meet at the big dinosaur on the first floor. If you're going to a sporting event, choose a large visible landmark -- the hot dog stand, the ticket booth. You get the idea. Tell the kid to head there if they can't find you.
I want my kids to remember my phone number, but the younger one is still struggling with this. You can get temporary tattoos with your phone number, or in a pinch, write it on their arm with a Sharpie. Another line of defence is stickers with their name/your phone number to label their clothing. If some adult finds them wandering, the kid can show their tattoo or name label.
If you kid doesn't have a phone, you can give her a walkie-talkie. My kids are too young for this -- they'd just play with the walkie-talkie -- but I imagine it would work for slightly older kids at big events such as fairs and carnivals.
If You Fan Out, Set a Time Limit
I made this mistake when I lost my kid in the park -- I asked my older son to go look for him too, but I didn't tell him "come back in five minutes and meet me at the fountain", which means I was, for a brief, awful moment, wondering where both kids were.
If all else fails, there's always the leash, a totally honourable solution, IMO, for any parent with a darter. If my kid runs again, you can bet I'm going to totally strap him to my side. In the meantime, if you see an unaccompanied kid waiting by the dinosaur at the Natural History museum, check his arm for a tattoo.