Maybe you can find someone in one of your classes that can help? A study buddy or someone to just email/text/call you every evening and give you that evening's assignment?

I have a calendar and post it near where I do my work and/or a copy to carry around with me so I can note appointments and dates when they come up. Every morning when I get up I look at it first, as part of my journaling/getting "ready" for the day ahead to see what's on my to-do list, calendar, what I'm thinking/wanting to do that day.

Maybe you can think of a little reward system to help remind yourself? Assign a favorite artist to each class and get a song from napster or Amazon or iTunes, etc. by that artist for each week you write down all your assignments in that class?

Make a personal connection with the class/assignment right away when it happens. If you're assigned something in an online class, go to the class and look at the assignment and think about it when you're not there so you can't forget it but are anxious to get in there and reply? I had a lot of rewrites of the same material to do over and over once (could get additional points if I added "more" of what was wanted) and finally I spent a whole weekend writing the whole thing in verse! Took me hours to write about 5-10 pages but I didn't forget that material very fast since I had had to work so hard to write it as poetry, LOL.