I was just checking out the Google +1 sprite and it’s pretty impressive. The file size is 3,290 bytes, which is pretty damn small, considering the the dimensions and the amount of gradients in it. Kudos to the google pixel pusher who put this one together.
Nonetheless, I wonder why there’s 1 pixel of space between each icon… so I created an alternative version. Here’s a PNG saved at 200 colors with transparency. 3,099 bytes. Not a big difference… but I wonder what it calculates to at scale.
It can be losslessly crushed even more with a few rounds of pngcrush/pngout/optipng/advpng to 2640 bytes. The original crushes down to 2789 bytes.