Hey All,
I knocked together an abstraction to make loops of midi note data:
http://mccormick.cx/viewcvs/*checkout*/s-abstractions/s-midiloop.pd?root=svn http://mccormick.cx/viewcvs/*checkout*/s-abstractions/s-midiloop-help.pd?root=svn
You specify a loop length in timer ticks and optionally a midi channel. The rest is pretty self explanatory. You will probably want to check out all the s-abstractions (required for the help file to function properly).
http://mccormick.cx/viewcvs/s-abstractions.tar.gz?root=svn&view=tar
This is sssad enabled so you can quickly and painlessly save your loops between sessions.
If you want to record control data instead of note data you might like ot try out [s-midimemory] which records a midi control data stream and loops it when you turn the knob/slider all the way to 127. Good fun for making it sound like you have more than two hands.
Have fun!
Best,
Chris.