Tracktacular needs to have a clean, clever, web 2.0 style logo that is backed by quality above all else.
Designers are encouraged to be creative, I have no strict requirements except that it needs to be clean and clear. I prefer the standard web 2.0 colors, blue in particular, but I am also a fan of green and subtle but sharp reds.
It may help to show against either an all white or all black background, but please no gradient backgrounds.
And I am particularly a fan of clever implementations. Tracktacular, by its own name, introduces some fun into keeping track of things, so it doesn't have to be all business. But I want to caution not to make it too gimmicky or childish, as I want it to represent a site that will do a good job of keeping track of your life.