I often use Homebrew Tone Transfer Method to produce my PCB's, but I use DorkBotPBX to produce my manufactured boards.
Laen (the owner of DorkBotPBX PCB) is now using a new web site: OshPark.com and using a new interactive process for submitting PCP designs. The new web site was introduced at the Bay Area Maker Faire 2012.
The site accepts Eagle and Generic ZIP'd Gerbers (as exported from DipTrace). The interactive process receives the ZIP'd file and renders the design, showing the individual layers and what the board will look like when finished (in Laen's standard Purple color). Very Cool.
The price is the same, $5.00 per square inch for a set of three, two sided boards.
Check it out at: OshPark.com