Is there an iPad whiteboard that can also be used on desktop machines? I've seen many iPad whiteboard apps but all seem to be either iPad only (eg Whiteboard Mojo) or are read-only from the web (Jot) or require local connection via wifi (splashtop) or make you pay for every Internet session (whiteboard HD). I don't mind paying for the app, but I want to use this for business, and nickel and diming per session isn't going to work. (How would people get reimbursed?)

So I want an app I can buy once and use for as many Internet whiteboard sessions with other iPads and desktop machines as I want.
This seems like it would be a good solution for you. No installation required, it should run on almost any desktop.
A Web Whiteboard

This product also may meet your needs.
NotateIt