Please check out our Web site at http://tweetspinner.com (it is NOT necessary to use the current design/colors of our site, as we plan for site redesign, too).
The logo should read horizontally so we can include it in a small top bar (although it can "expand" outside of the top bar). It should ideally be legible on light and dark backgrounds... (the dark background version can be reversed out.)
It should include both a small non-text mark which we can use as our Twitter profile image (currently we use a sun), as well as the "tweetspinner" text. The theme of the non-text mark could be literal (in terms of the "spinner" part) or figurative (such as something which suggests connecting with customers/friends) or something different. It would be nice to see design options which are markedly different than other options other designs have already offered.
The inclusion of ".com" at the end is optional, although we generally prefer to not include.
For legibility, differentiation between "tweet" and "spinner" should be clear.
There are no requirements in terms of capitalization and so we are open to suggestions. (We currently lowercase the logo.)
(Note that the logo doesn't need to be designed with the current Web site design as that may soon change... another 99designs contest soon after.)
Please read our comments at the bottom of the contest for more nuance on what we are looking for.