Big Data for The Small Guy
The first tool is TweetStats (http://www.tweetstats.com/). This is a simple tool and delivers stats on tweets per hour, Reply stats and more.
The second tool is BrandTweets (http://stats.brandtweet.com). This tool will let you compare your twitter account with any of your friends or foes (as long as you know their twitter handles).
Enjoy the tools and do let me know if you find others that you like or hate.