If you're not sure what name to give, just type in any strange name into G. And if G doesn't show up any search result, that means you own this name
So, after you've created forum profiles using this name and done all the ping and rss... wait for a while. Type in this strange name in G to see whether it shows up.
Simple and it's free.
Btw: G index this post within 10 mins. There's no ping or rss here.