Check this out 1. buy domain 2. point to nameserver 3. use cpanel to install phpbb 4. login to admin of phpbb 5. Googlebot is listed as hitting the forum This is all I have so far http://www.phpdictionary.com/ We're talking 10 minutes max. There are no known links pointing to the site! WT*!
But the question isn't how soon they crawl it. The question is how soon they list in the SERPs. I'll bet you find it on MSN before you find it in Google. The other question is did you put up any links to it before you installed it on the server? Because if you didn't how did they find it, unless of course you had AdSense scripts on the site and then the suggestion about the AdSense bot is probably the explanation.
Part observation of forum activity, part speculation based upon the most recent Google patent application: http://www.google.com/search?hl=en&...,GGLC:en&q=google+patent+domain+registrations
I just checked the stats for a domain which I bought over a year ago and have not developed yet. It has had a single page up since I bought the domain (my own page, not a web host parking page). At any rate. The site/page has had consistent traffic of 1 visitor a day and visits from Googlebot and Inktomi Slurp make up 90% of the traffic. The only referrers listed are whois.sc and Yahoo search. I have no idea why Yahoo is showing my page in SERPs when the only link pointing to it is from whois.sc (but it looks like it may be time to develop that site...).
When you whois a site such as yours, it will be stored and google with crawl that information. I have several sites i havnt even put a page on yet and still i am seeing google and msn crawl it. On the otherhand as said, this could quite possibly be the adsense bot ( he does not waste time)
I've seen the same thing happen with Yahoo twice. Yahoo has hit two sites while I was installing and tweaking the code just after the DNS changes kicked in. Both times it resulted in garbage content in Yahoo's database until the spider returned. There were no inbound links to either of these sites and I do not use the Yahoo toolbar. I speculated that Yahoo is somehow monitoring DNS changes. I have not yet seen Google or MSN do this, but it sounds like others have.