Clicktotweet - promote and advertise your stuff on Twitter

"Clicktotweet is the best, easiest and simplest way to promote and advertise your stuff on #Twitter"

twitrounds - free Twitter backgrounds

"twitrounds was established to help provide high quality #twitter backgrounds for all you twitter lovers. We want to do the hard part and make creative, good looking backgrounds. All you have to do is find the twitter background you want. Once you find that background, simply install it and enjoy! We will continue to add backgrounds daily" RSS Feed

TweetSaver

"TweetSaver is a nifty web service built by Squeejee. TweetSaver gives you the means to archive, search, tag and share all of the great content you create on twitter"

TweetConvo

"TweetConvo is a new way to view #twitter conversations. Long gone are the days of going through all of a tweet's @replies to get a grasp of the conversation. All you have to do now is enter a tweet's URL"

TwitRes

"TwitRes lets you share resume/cv on #Twitter. It's the fastest way to publish your resume online"

ScreenSnapr

"ScreenSnapr - an easier way to share screenshots has finally arrived. Simply press the ScreenSnapr Hotkey (Ctrl + 1), and almost instantly have access to a URL to share on IM, #Twitter, Email, or any other virtual medium"

ScreenSnapr Intro from ScreenSnapr on Vimeo

pretweeting

pretweeting - "make a (virtual) profit by buying and selling words on #twitter. Predict what's going to be hot and buy it up before it hits twitter, and you'll make a killing once people start talking about it. (no actual money required!)"