Matt from Berg here, makers of @littleprinter.
Thanks for the link, lovely comments :) Our office Little Printer is going crazy with people testing the open API (it's at the bottom of the homepage).
So you might also like this: We're beta testing an off-the-shelf receipt printer with the same API back-end and HTML renderer in the cloud. Check it out here: http://littleprinter.com/business/
It turns out this is a solution people like - our evaluation kits are selling well - so there's also a provisional roadmap on that site. We're seeing a bunch of web startups extending their service into hardware using this device.
I'd love to hear any feedback you have!
Little Printer