Don't really see much of a point for PSN Home but then again, not everyone is like me. I tend to have the laptop around me when I'm on the PS3. That way, if I get stuck at a particular part or want to play multiplayer, I can look around on the internet for people to play with right away.
I guess it's cool to be able to customize my avatar with unlockable/buyable clothing and have my own personal space to decorate, but that's really just about it.
Oh, you can also just plug in a USB keyboard to your PS3 and it'll work just fine as a keyboard. Better than buying one of those puny PS3 Bluetooth keyboard controller attachments.