Minimizing your contacts in Wave will give you a much longer list to view when popped down. You can also minimize the navigation box and give yourself the whole lower area for waving.
Background on this post: Tweetie listed Posterous as a photo display source for Twitter so I decided to try it. From Tweetie, it posted the tweet with a link here but it tossed the picture up in an untitled post. No context if you follow my Posterous blog only if you arrive via Twitter. Not acceptable.