We’ve gotten our hands on three free passes to the Web 2.0 Expo in San Francisco on April 15-18, valued at $1,500 each. We traded these passes for excess advertising inventory on our sites, and our plan is to give them away to readers.

I want to have some fun with giving these out. Last year we gave away a free pass to SXSW to the reader who had the best reason for going, but it turned out to be a massive competition for the biggest sob story. It was depressing.

So for the Web 2.0 Expo, we’re going to do something a little different. I want you to tell me how much we (occasionally) suck. Sometimes our predictions are, with the benefit of hindsight, way off. Or they had no logical basis to begin with. Or perhaps we got some crucial fact wrong. Whatever it is, I want you to dig out the worst post in TechCrunch history and write about why it’s so bad. A good place to start is our Company Index.

Here are the rules: You can attack any post published on TechCrunch (not MobileCrunch, CrunchGear or any of our other sites). But you can’t personally attack the writer unless it’s me (Michael Arrington). Points will be given for originality, creativity and humor, but deducted for outright and unsupported meanness and/or ad hominem attacks. The best entries, in my opinion, will be the ones that find us stating a one-sided opinion about the future of a startup or market segment that turned out to be flat out wrong.

To enter, you need to write your entry on your blog and either successfully trackback to this post or add a link in the comments to what you’ve written. If you don’t have a blog, I recommend starting one at Wordpress, Vox or Blogger. It only takes a minute to set up, and hopefully this will be the first of many interesting blog posts that you write.

We’ll pick the top ten or so entries and then let readers vote for the three winners. Entries must be written and added to the trackbacks or comments below by noon PST on Saturday, April 7 (comments and trackbacks will be turned off at that time). The voting will start on Monday, April 9 and go for 48 hours.

While this is mostly for fun, I’ll be reading every entry carefully and pulling out as much constructive criticism as possible. This will be a painful, but useful, way to become a better writer.

Update: Wow, I regret this already. Even our former writer Marshall Kirkpatrick is piling on.