For running a brake on a non-machined rim, the best thing to do is to use cork-type pads, which are originally meant for carbon rims. You can buy these as inserts for regular shimano or campag types cartridge pads. They don't tend squeal like a moaning whore like rubber pads do, plus they don't seem to mark the rim as badly too...but of course there will still be marking! The only downside is that they can wear down pretty quick...makes for a good excuse to try and stop using your brake though.
For running a brake on a non-machined rim, the best thing to do is to use cork-type pads, which are originally meant for carbon rims. You can buy these as inserts for regular shimano or campag types cartridge pads. They don't tend squeal like a moaning whore like rubber pads do, plus they don't seem to mark the rim as badly too...but of course there will still be marking! The only downside is that they can wear down pretty quick...makes for a good excuse to try and stop using your brake though.