The logo in the header of this site is a raster PNG file (portable network graphics). I’m unsure if it’s worth changing it to a different file format, but it was interesting to read Jeremy Frank’s mini-series about using vector SVG instead (scalable vector graphics).
Detail reduction from the Argento style guide (PDF)
- Responsive logos, part 1: Tips for adapting logos for small screens
- Responsive logos, part 2: Making logos truly responsive with SVG
You’re probably familiar with Joe Harrison’s responsive logos gallery where he showcased the concept (view in a browser you can resize for full effect).