There have been a few articles recently about Google\'s new imageless buttons:
This is their "Archive" Button, according to Firebug.
The CSS is more than I care to organize/paste for this. Perhaps it's just me, but when the markup/css become this heavy, I think I would much rather USE AN IMAGE (or a couple images as backgrounds. Better yet, Sprites). Besides, an image for this button would be less than a single K.
As much as I love Google, this seems a bit overkill.
Update: Google is a unique case. If you're a massive site and you wish to internationalize your content, then this image-less technique is actually really cool. It allows you to apply just about any written language to your UI, without needing to generate new images, or fear of breaking your buttons.
See Question: What are the advantages of using an imageless button?