The http://nextgl.ngemu.com/ site has released a neato tool for the VMU, heres the news from this site.
VMI Tool is a utility that can be used to simplify the process of saving data to the VMU using the Dreamcast’s web browser. VMI files can be stored on most web sites and allow Dreamcast users to download VMS files directly onto their VMUs. The VMU files can either be saved game data, VMU games, or VMU icons.
Cool eh check out the link above