If you have a lower screen resolution you might appreciate this latest Gmail feature in Gmail Labs if you use labels. You can now hide labels so you can see the email subject line, mostly for notebooks and netbooks.

On smaller screen resolutions – or whenever your browser screen isn’t adjusted wide enough – you may only see the from email address, some labels and… well that’s it (see the link above for a screenshot).

I guess if this one takes off you might see a button in the main Gmail screen for it later.