If orangutans can, then toddlers can certainly Twitter.
When a child presses a certain picture for a select amount of time, software captures sensor data from the activity center and selects and sends a predefined text related to that data.
For example, when Bobby plays with Mom's picture for more than three minutes, a Twitter message will post to Bobby's personal Twitter account saying, "@mommy_bobby Bobby misses mommy and looks forward playing with her this evening" (or as the messages get more refined and personalized: "@mommy_bobby Bobby is having a temper tantrum and wants mommy home now."
Twittering toddlers can also communicate with their social-networking peers by pushing buttons that generate effects, such as colored, blinking lights, on their friends' Twoddlers (a scenario that could easily turn day-care into a disco). Twoddler is connected to the Internet and to other activity centers using the home area networking standard ZigBee.
Twoddler emerged from a course on mobile and pervasive computing at Belgium's Hasselt University. Earlier this year, Twoddler beat out around 40 submissions for the top prize at the 09 Innovative and Creative Applications competition, where judges called it a "good, well-implemented idea, with a lot of potential that allows people/children that are not capable of verbal communication to communicate through an inventive combination of hardware and software."
As we mentioned, Twoddler is just a prototype for now, so don't expect to get an endless stream of tweets from your overexcited 3-year-old just yet.