I came across Tweetstats from new Twitter follower @hjortur. Tweetstats provide you with some stats that reflect your Twitter usage from day one, the day you sign up for Twitter. (my results)
It aggregates the number of Tweets from when you signed up to present day, and gives you stats on how many tweets you've posted each month, how many tweets each day, at what time of day you tweet the most, the people that have @'ed you the most and the most common interfaces you use to tweet. Phew, that's a lot of info!
Seems like I was at my peek Twitter usage in September '07.
On average I tweet the same amount each day, except for on Sunday, I take a Twitter break.
I tweet the most just after lunch. 
I am Joec0914 #1 fan ;)
I use the Twitterrific application the most to post tweets.
