Gmail is a cool web app. From a user's perspective, it's very nice, very responsive. From a coder's perspective, and in particular from the perspective of someone willing to tweak a little bit Gmail's UI, it's a nightmare though. Gmail uses a frameset and so many iframes that you have to manipulate a lot of documents. In front of me right now, I have roughly 15 iframes, and they're not used for ads but for real useful content. Geeeez.

Please Google, get rid of frames and iframes as soon as possible. Seriously. Sergey, you used to read this blog a while ago, please drop those painful frames and iframes for real content and move to real dynamic pages.