[Rich Breen]

I believe you could achieve this by taking a straight 1/4 note click or midi track, 'randomize' it with the Quantize operations window, then use Beat Detective to build a tempo map based on this randomized 1/4 note track. Haven't done it, but I don't see why it wouldn't work. OTOH, most people I know who are trying to 'humanize' tempo feel build click tracks that speed up and slow down according to the song structure - this makes more sense to me.