I think just about every kid I knew, including myself, had sea monkeys. Now, that we're all adults I think I let the cat out of the bag and call them what they really are - brine shrimp! These fantastic little creatures provided either hours of amusement or instantaneous disappointment. If I recall correctly, it didn't take long to figure out if they were going to hatch or if the cysts were duds.
Just for kicks I went to google and performed a search. I had no idea sea monkeys were such high maintenance! They have medicine chests for them containing vitamins and there are even ways to spoil your new best friends - with treats and things for them to crawl all over. It's actually really neat, considering it's just brine shrimp. Here's the link to the main site I found.
Did you have sea monkeys as a kid? Do your kids know what they are?