you can change the limit within php.ini iirc, but for those big files it's better to ftp upload
but if the file is on the server and not in the db, it's harde to save them by the vb account, as once someone got the link, everyone who knows it can access it.
i think there is a way around it, but i don't have the time to write it right now, but as it's a request i leave the field for someone else now