In the past, I have had students use the PECS (Picture Exchange Communication System) primarily for visual schedules. This is great for our students with autism as it gives them visual cues as to what's coming in their day and an approximation time-wise as to what is happening (ie: no surprises). It can also be used with token boards, as you can visually cue the student as to the rewards they can receive after achieving the desired number of tokens. Additionally, non-verbal students can use the pictures as visual cues for such things as directions for how to do something (ie: step 1, step 2, step 3). It is a low cost means of communication as well as easy to use. Students can also be trained very quickly on how to use it. A good video on the practical usage of PECS is on www.youtube.com:
http://www.youtube.com/watch?v=c9ywf0WDoj0