My youngest child just got her first email account. She now knows how to login to her Gmail account and send emails and gchats to her parents, brother, grandmother and uncles.
My oldest child got his first account when he was five, and it really helped him learn to type, spell and successfully navigate web apps. Today, it was Michelle's turn to enter the digital fray. We fleshed out her contacts (the only people she's allowed to email are those I bless in her contacts), gave her a cool profile picture, changed her Gmail theme to "tea party" and taught her how to compose emails and send instant messages.
Nothing's cooler than getting an email from your 5-year old daughter, even when it's just a heart icon. Especially when it's just a heart icon.