So its a longshot, I\'ll start with that.
Is it/could it be possible to discover bonjour advertised HTTP services in javascript alone?
Why would this be usef
The short answer is no ( at least not on the Linux platform ).
Funny you should ask: I have been working on bringing this sort of functionality within reach of web browsers. One of my success in this endeavor is an NPAPI mDNS plugin for Chrome. The plugin basically interfaces with Avahi ZeroConf (mDNS - Multicast DNS Server).
I am currently working on yet another bridge to close this gap: a "lightweight" database ( a la CouchDb ) that will be used by desktop applications to register their HTTP end-points. Extensions would then read those end-points from Javascript and be able to interact directly with the advertised services.
UPDATE: There is hope through W3C Service Discovery.