Check out this Mini Tutorial on creating bass lines using randomisation techniques in Reason here: [url]http://www.macprovideo.com/blog/propellerhead-reason/randomization-reason-quick-bass-line[/url] :)

You can also use the tool windows randomize function to limit how far up or down the scale you want to go. I have a launchpad template set up with the pattern up,down.left,right alter and rand functions. You are dead right this is one of the best ways to generate some wicked basslines.

Thanks for the tip CJMorph.