I just checked the "educational" Canadian Apple Store. Maybe it is different in other countries, but in the section where it lists the purchase limits (1 Macbook per year, etc), it clearly states there is no limit on iPods. I guess you can buy as many Canadian discounted iPods as you want! It can come in handy when you have to buy the latest version every 6 months.
Also, for what it's worth, I was able to access and get to the final stage (confirmation) of ordering a macbook just by picking a random school and typing in a random student number. Does Apple actually check before shipping? I might just give it a try.