Google has announced that it is going to be indexing the web in real time:

Now, immediately after conducting a search, you can see live updates from people on popular sites like Twitter and FriendFeed, as well as headlines from news and blog posts published just seconds before.

[…] You can also filter your results to see only “Updates” from micro-blogs like Twitter, FriendFeed, Jaiku and others.

[…] Our real-time search features are based on more than a dozen new search technologies that enable us to monitor more than a billion documents and process hundreds of millions of real-time changes each day. Of course, none of this would be possible without the support of our new partners that we’re announcing today: Facebook, MySpace, FriendFeed, Jaiku and Identi.ca — along with Twitter, which we announced a few weeks ago.

This announcement should make people with twitchy Twitter fingers pause. There was once a time when a mis-posted Tweet could be deleted in time to ensure it never made it into Google’s cache (although never fast enough ensure no one saw it in their timeline). Google hasn’t explained how they will now deal with deleted updates, but my own experiment this morning showed that deleted Tweets are not deleted from Google in a timely fashion (if at all).

This is good and bad news. On the one hand, Google Cache has allowed me to do a bit of forensic Twitter searching to piece together deleted conversations. There will be times when it will be an important tool for holding public figures accountable for what they say in public. On the other hand, everyone makes mistakes. Shouldn’t we be able to delete and forget them?

However Google ultimately decides to deal with deleted content, it’s a timely reminder not to update in haste.