I basically rewrote this entire set so they are full vector buttons, meaning:

• @font-face icons
• custom font file for all social icons
• icon font use private unicode spaces for accessibility
• em sizing based on button font-size
• support for about 81 different services
• buttons and icons supported
• no raster images (sweet)
• works splendidly on any browser supporting @font-face
• CSS3 degrades gracefully in IE8 and below etc.
• also includes generic icon-less primary and secondary buttons

<button class='zocial facebook'>Button label here</button>

or

<a class="zocial twitter'>Button label</a>

• Can be any element e.g. a, div, button etc.
• Add class of .zocial
• Add class for name of service e.g. .dropbox, .twitter, .github
• Done :-)

Check out zocial.smcllns.com for demo and code examples.

Problems, questions or requests to @smcllns