Twitter's workforce grew in terms of both size and impressiveness this week. The company has named its first CTO (promoting a current employee), and also hired someone away from Palm to act as its vice president of engineering. Let's start with the top-level move. Greg Pass is actually Twitter's old vice president of engineering - he held the role for about two years. Before that, he served at Summize, AOL, and ToFish, and earned a degree from Cornell, as well. Presumably,