Apple's iDisk is not Mac/iOS only. Any WebDAV client can access it. I use it on an XP machine without any extra software. In fact, using an open standard like WebDAV is probably the reason for iDisk's performance issues. Any WebDAV "disk" I have ever connected to has had performance issues.

> except for google

Well, no. You can upload any document you want on google docs now. And they give API to manipulate, there's a company that offers a dropbox like solution based on this. Google it.