*Update 21st March 2014* On Twitter’s 8th birthday, Twitter launches first-tweets.com , where you can use it to find your first tweet! Just type in your @username, or that of anyone — your best pal, favorite comedian, a star or a president.
*Update 25th February 2013* It seems that Twitter has been rolling out the ability to download your Twitter Archive  to most users already, I have created another tutorial for this feature, lesterchan.net/blog/2013/02/25/twitter-archive/ .
Inspired by DK’s blog post on Been using Twitter for 3 years and still loving it! , I am determined to get my first tweet. But there is a problem! The 3,200 tweet limit imposed by Twitter.
According to Twitter’s FAQ , it states:
Why can’t I see all my tweets? My tweet count is _,___. Are they lost?
The good news is they’re not lost or gone! We have all your tweets. The bad news is that we currently only allow you to see the 3200 most recent tweets (this could also be construed as good news, as that number could be lower than 3200). The other good news is that we are eventually going to build something that will allow you to see ALL your tweets. Among the gazillion things we want to do to make Twitter better, this hasn’t yet reached the top of our list, which is largely based on what we hear from people like you. At some point, you’ll be able to get on a twime machine, visit your twistory, and tweminisce. That will be a fun day!
That means if you got more than 3,200 tweets, you are pretty much screwed if you want to get your first tweet. There are services like My First Tweet  and My Tweet 16  which allows you to get your first tweet.
My Tweet 16 did not have a gracious way of telling user, “hey you got more than 3,200 tweets and hence we can’t obtain your first tweet”. Instead it still displays the so called “your first tweet” which is totally fake if you got more than 3,200 tweets. It is basically listing your (YOUR_CURRENT_TWEET_COUNT – 3200)th tweet.
My First Tweet on the other hand is much better, if you got more than 3,200 tweets it will just prompt you “Sorry, something went wrong. This is what I have recorded as your error: Too Many Tweets.”.
I tried Googling, Binging and Yahooing but still could not get any answers. Suddenly Internet Archive  came to my mind! Just enter your Twitter URL which is http://twitter.com/YOUR_USERNAME. For mine, it is http://twitter.com/gamerz .
It should be able to list the archives of your Twitter page, click on the earliest archive and it should bring your to a cache page of your Twitter page during that period. Here is an example http://web.archive.org/web/20080118191247/http://twitter.com/gamerz .
As you can see, it list down all the tweets that you have during that period. That page listed 4 tweets for me which matches the Updates count on that page. And hence the last tweet on that page should technically be your first tweet. There is no way to confirm that till Twitter have a time machine or something in the future.
Here is my first tweet  according to the Internet Archive:
After midterm exams, now comes exams