Meow … Want to Be My Friend?

She's from Toronto, Canada, enjoys running, jumping and eating steak, and has 43 friends on her online profile. But social network user Annabelle is not a teenager — she's a dog.

Her breed is listed as a mutt, and her friends include fellow pooches Jasmine and Oreo, and a suspicious member named Chelsea, who is a cat.

Annabelle's owner, Geoffrey Roche, is an advertising executive who used the social networking site Facebook to create two networks for pets, aptly named "Dogbook" and "Catbook."

Just like humans, the animals can post pictures and send messages to one other (not surprisingly, the word "woof" comes up a lot). They can also find other animals in the neighborhood, and will soon share videos.

"You really join a community of other people who love their dog and love their cat," Roche said. "In my case, in fact, I have more dog friends than I do people friends."

In under three months, with no advertising, Dogbook and Catbook have attracted nearly 600,000 members. That includes new cat members Ruby and Zoe — owned by ABC's Dan Harris.

Harris tested out the site and said it took five minutes to set up a profile before he was able to meet cats all over the world, including China.

These profiles for pets are a sign of how silly, sophisticated and popular social networking sites have become online.

Facebook and MySpace are two of the Top 10 most visited sites on the Internet. Together they accounted for nearly 7 percent of all Internet visits last week alone.

"The more useful technology becomes, the more broadly it spans the silly to the serious, from the personal to the very, very public," commented industry watcher Xeni Jardin.

One of the founders of Facebook recently predicted everyone on the planet would be on the site in five years. Maybe their pets will be, too.