This is an idea for a new marketing and activist direction.

Declare Victory!

Tell the world that Schools are using open source.
Tell vendors that they must support Linux/Moodle/Open Standards as applicable so that schools using Open Source can use their product. Pressure and use grassroota techniques to advocate for Open Source compatible versions of all IT that schools need.

Here are some reasons this might be effective:

1. Its true
2. Even though we are shifting the aim of our message to vendor It will still reach schools and they will think hey, other schools are using it we should take a look.
3. Lack of ability to use X program or hardware is in fact one of the major barriers to adoption.
4. If a School decision maker goes to buy a piece of software and they see "download: Windows/Mac/Lin ux" or for a web service/content: "Works with: Moodle/Blackboard/Angel" that's great advertising!