Early adopters of Netbooks have a nice new option in Gmail, courtesy of a labs update that went out Thursday. The feature, called "message sneak peek" is a simple pop-up preview of the message. It's not a full version of the message, but in most cases it's enough to read the entire thing without having to leave your in-box.
The peek feature must first be turned on in labs. It can then can be summoned by hitting the "H" key on your keyboard (if you have a message selected), or by right-clicking on a message.
What does this have to do with Netbooks you ask? Well, if you're one of those users who bought a model with a small screen resolution, you're probably spending more time reading messages individually than leaving your in-box open, since you can only see so much text in the in-box message preview.
With peek enabled, you can just cruise through your e-mail (even with the normal "J" and "K" keyboard shortcuts) and never have to open up individual messages--that is, unless they extend outside of the sneak peek area. This gives you a better idea of when the message was sent, and its relation to other messages in your in-box. This change also brings use one step closer to having a real two-pane view, as.
The one slight drawback with this system, is that message peeks are not counted as a read, so you'll have to go back and check off each message as read in order to drop your in-box counter closer to zero. There is however, a "mark as read" button within each peek, which can be clicked without having to open up the full message.
Along with the message peek, Gmail also introduced a nested labels option to labs, which gives users a way to add hierarchical order to their labels. This actually gives labels a folder-like feel, while remaining within the confines of Gmail's labeling system. You can see an example of it over on the Gmail blog.