Yeah, most of those kind of chat programs need to be downloaded so I'm going to have to say that you're out of luck. In case you change your mind about downloading, some pretty safe cool chat programs are: Imvu.com , secondlife.com (don't really favor this one) , toontown.com , and Kaneva.com.
Edit: Yeah, there is Home on the PS3.. But that's only if you have a PS3 and Wi-Fi...