passive info gathering

From: Gary Hasty 
Anyone have a favorite tool (app or online) they prefer for some passive =
info gathering on domains/subdomains around the interwebs?  Just basic =
info from whois, scan of hardware/software, etc in a nice tidy package.  =
The more info and crawling it can do the better (such as identify =
storage, etc)
Gary Hasty
"The way to get started is to quit talking and begin doing." - Walt =