I came across Tim Harpers Bundle-fu plugin for Ruby on Rails and thought that there would be something similar for PHP (which is what I work in most of the time). After a bit of searching I had found a couple of methods for doing this but they all seemed to involve altering the way that files were included so I thought I’d come up with something myself that I could easily make into a WordPress plugin.
Initial tests of bundling the assets of my blog proved to yield some good results. I have several plugins enabled, all of which add their own files and bundling saves a round trip to the server for each one. I had a look at things using the LORI and Firebug Firefox browser plugins and the bundling shaves a few seconds off the page loading process. There is obviously an initial hit the first time that the bundle is generated but caching the results negates this issue.
Check out the code of the first version beta of Bundle PHP.