Tweleted hasn't worked since 2009.

Contact Twitter Support for help.

Wait, what happened?
Twitter fixed the bug that meant that deleted messages still showed up in Twitter search. Tweleted doesn't work any more! That's great — and it's what should always have happened.
I really want to recover those tweets...
If you're really that much of a stalker, consider using FriendFeed or a similar service that doesn't honour 'delete' requests. I can't help you any more.
Wait, you're celebrating?
Hell yes. I can't stand internet drama.

Here's the old FAQ:

What was Tweleted?
Tweleted allowed you to recover Twitter messages — tweets — after they've been deleted.
Who made it?
Hello. I'm Tom Scott. I live at tomscott.com, and you can email me or follow me on Twitter.
How reliable is Tweleted?
Unknown. It can, and probably will, miss some deletions and even describe extant Tweets as deleted. Tweleted cannot tell the difference between tweets that have been deleted and those vanished temporarily through Twitter database problems.
How is this possible?
Deleting a message from Twitter itself doesn't delete it from other sites, including search.twitter.com. Tweleted works by automatically comparing the results from the main Twitter API with those from search.twitter.com; anything that appears in the latter but not in the former is likely to have been deleted!
How far can this search back?
Depends on the user and how the Twitter API is feeling. Generally up to about 1000 messages or three weeks, whichever comes first, but that can vary a lot.
It's broken!
Quite possibly. This was coded in a few hours' frenzy after getting the idea, and there are almost certainly bugs.
Whoa, I'm getting a username and password prompt! Are you trying to scam me?
It's a flaw in the Twitter API - if you search for an account that doesn't exist, or accidentally copy-and-paste in an extra space, Twitter will (for some reason) return a request for authentication. That request is coming from Twitter and, whether or not you answer it, I cannot see what you enter.
A load of private Tweets showed up here!
You're searching on an account that you're already logged into Twitter with via HTTP authentication. Close your browser, restart, and you'll find it's gone.
Why am I keep getting a message saying I've hit Twitter's limit on searches?
To avoid Twitter's servers getting overloaded, you can only issue around 100 requests per hour to their API. A search on Tweleted can use up to 15 of those straight away, so after a few searches you'll find yourself hitting that limit. Come back in an hour.
Are you storing the messages I've deleted?!
No. All the processing of messages is happening on your own computer — I'm not even storing a record of which usernames have been searched for, let alone the messages that have appeared. This site isn't doing anything special — it's just automating what was always possible manually.
How can I delete my messages from here and from search.twitter.com?

Twitter have written an FAQ entry on removing deleted updates from search.

First of all, let me apologise. Tweleted doesn't do anything that wasn't already possible manually, but I understand that having it so visible can be uncomfortable.

All the processing for Tweleted happens on people's own computers, though, and my server isn't involved at all. That means there are no logs of who's been searched for or what tweets have been found; but the downside of that is that I can't invisibly disallow searching for some users.

Basically: I can't add an exception without creating an "exception list"... which would be visible to any user with mild amounts of technical experience, and instantly make your own history much, much more interesting to them. I can also guarantee that if I did censor the results, someone would, within hours, set up an "uncensored" version of Tweleted explicitly designed to search - and advertise - those users on the exception list.

I have another question!
Email me. I'm friendly. Oh, and, since this seems to have gone viral, I thought I should mention that I'm looking for work doing web, video and viral stuff. Just in case.
I want more information!
For the full details, and a lot more information about Tweleted, have a look at my presentation from BarCampLondon6.