Ha ha, I have both versions. Though HG belongs to my sibling.
I too haven't looked at the PokéWalker yet, much less used it, but I might do so within the next few days considering the Yellow Forest event is coming up.
I'm playing HeartGold...although I had Silver as a child, SoulSilver didn't have native Growlithe's so I went with HeartGold. I've had it since Saturday and I haven't even looked at the PokeWalker yet, xD
Actually, yes I have. Plus, it's a newer account from my old one. I'm Quick_Kid aka f l a s h aka Aero. and now the name is Kyone on that account. XD; Anyway, remember me?
I know, it's how we started talking to one another before.