One solution we've used when we've exhausted other modalities is to have the student take a snapshot with an iTouch.
I like to make a box for the teacher to write in, using electrical tape on their white-board. This serves two functions: 1. the teachers have an area dedicated for homework (this can help our scribing students as well), and 2. it serves as a visual cue for taking the photograph.
Once the picture is taken, the student can email it using the built-in software to do so. We ask the student to mail it to an email they share with a parent. The other option we've used on occasion is to load the picture up in Dropbox or iCloud. Using Dropbox or iCloud, we want to be certain the accounts are shared with the parents, and that they are emptying the photos at the end of each week.
Whether the student emails the photo or moves it to a "cloud" server, the picture will have a date and time associated with it automatically, which further helps reduce confusion.
I'd love to hear if you are using the iTouch camera in interesting ways.