Google indexed my post in under 2 hours

I've always wondered how long it took Google to update it's indexes. I'm sure they have pre-scheduled updates -- or even dedicated 'spiders' -- for more popular and active sites. I've setup small personal sites before but then never saw them appear in any search engines.

But today I posted a new question on UbuntuForums.org and when I tried to Google for an answer about 2 hours later I got my own post as a hit. So I guess that solves that question!