I teach a jazz band at a college in NJ, and I've found that teaching other musicians (non-bassists) to "walk" can be an effective way to get beginning improvisers started, and to improve guys who can play but really aren't making it. I have them first write and then improvise quarter note lines with chord tones on 1 & 3 and connecting or embellishing notes in between. This gets them really hearing the tune and trying to groove. When this becomes fluent, they can begin adding rhythmic embellishments etc. I think we bassists have a head start on everyone else if we really try to walk creatively. Instead of us trying to be "horn like" during our solos other cats should try to be more "bass like."