Naming your Application or Product, Applying for a Domain
We understand that you want your application or product that enhances the Twitter experience to be identifiable as part of the Twitter ecosystem. This is important to us too, but Twitter is also the name of our service and company, so we're cautious about potential confusion.
Do:
1. Name your website, product, or application with something unique. Uses of Tw-, and Twit- are generally okay with us.
2. Feel free to include language on your site explaining that your application is built on the Twitter platform so people understand your product.
3. Use Tweet in the name of your application only if it is designed to be used exclusively with the Twitter platform.
Don't:
1. Use Twitter in the name of your website or application.
2. Use just "Tweet" or "Tweet" with a simple letter or number combination (for example, 1Tweet, Tweet, Tweets).
3. Register a domain containing twitter (or misspellings of twitter).
4. Apply for a trademark with a name including Twitter or Tweet (or similar variations thereof).
5. Use Tweet in the name of your application if used with any other platform.
I looked at this, but with Twitter being very TM sensitive, I opted out! 
Although I don't think they TM'd the tweet term, despite trying?
