One of the major stumbling blocks when considering whether to implement a CSS3 feature is the plethora of vendor specific syntaxes. Implementing even a relatively simple feature such as border-radius can lead to lots and lots of CSS:
border-radius: 10px 5px;
Not only is the code verbose, but remembering the various vendor syntaxes and identifying mistakes requires a good memory and hours of cross browser testing.
The obvious solution to all this seems to be to use a tool that will convert standard CSS3 syntax into the various vendor specifics consistently leaving the developer with a pure undiluted CSS3 stylesheet.
So does this tool exist?
In terms of efficiency, converting files just the once on the server side would be the best solution. There are already a couple of CSS tools (LESS and SASS) that do a similar thing with CSS, but not specifically with the CSS3 syntax.
Watch this space...