"BrightKit is the ultimate Twitter toolbox. With BrightKit, you can manage multiple Twitter profiles, pre-schedule tweets, and measure your success." - well the name resemblance to 'Brightkite' might confuse ppl. thios also looks like it might be used to spam.
"Twittertise allows you to advertise on Twitter and track the success of branded communications with your customers.
Using Twittertise you can schedule your communications on Twitter and using URL tracking technology measure the effectiveness of your traffic driving techniques on the platform." -- I am not sutre I like this kinda service as it might lead to spamming.