memoization is your easy caching friend

def zipcode_and_name
  @zipcode_and_name ||= "#{zipcode} #{name}"
end

The ||= operator is a so-called conditional assignment that only assigns the value on its right to the variable on its left if the variable is not true. Since pretty much everything in Ruby evaluates to true when coerced into a boolean (except nil and, of course, false, as well as a couple of other things) this is exactly what we want: The first call returns the actual string and from the second time on, no matter how often the method is called on the same object, the “cached” result will be used.

Facebook spam detection: We need a link spam detector for all of the Internet.

New warning explaining why content has been blocked.

With billions of pieces of content being shared on Facebook every month and bad actors constantly targeting the people who use Facebook, preventing spam isn't easy. Just as a community relies on its citizens to report crime, we rely on you to let us know when you encounter spam, which can be anything from a friend request sent by someone you don't know to a message that includes a link to a malicious website.

via blog.facebook.com

At Posterous we deal with our fair share of linkspam and blackhat SEO link-building scams.

We need a revolution here. Perhaps with Facebook's lead. They have probably one of the best ideas of what links and link farms are evil. I would love it if they opened up an Akismet-like service to identify spammy content or spammy links.

Or maybe we'll just build it ourselves. We'll see. But the user generated content world is threatened by a sea of bad actors trying to get their illicit pagerank or get that one eyeball to buy one more penis enlargement pill.