I posted this on the Ableton forum and I guessed it might be of some interest here too. I am pleased to have finished my first pair of max externals, specifically designed for use within max4live, . This is no 'ready made' live device, these are only max objects which, if you take a look at the help patches, will enable you to build max4live devices with full access to sending and receiving midi events - notes/cc/program change/channel aftertouch/poly aftertouch/pitchbend and sysex from outside of Live, and without channel restrictions. These objects can equally be used in maxmsp, but differ only slightly from maxmsp's midiin and midiout objects.
Unfortunately for you windows users, these are mac only, and I have no plans to delve into windows midi frameworks, sorry. For windows developers, any source code would be of limited use as generally the code is quite simple. The head scratchy bit was doing all the coremidi integration... especially as I'd never looked at mac os frameworks before a couple of weeks ago.
Feedback is most certainly welcome on useability, robustness and feature requests.
I'm also interested as to how anyone might end up using these in their max4live devices, if indeed you do.