Bluddy (& others)
I suggest having an online Dropbox account - 2GB storage free, and it synchronizes on your hard drive. Just keep the spreadsheet in the dropbox/public/ folder on your harddrive, post the "public link" to the file, and we'd be able to get the latest spreadsheet without you having to re-upload it.
(link for a dropbox account)
I use it to sync files between my laptop, desktop, iPad, and I have a couple folders for graphics files shared with frequent-flyer clients who constantly have projects in the hopper. I was going to suggest it for the Din's Additionals plug-in too because the free file storage site he's using is a little annoying.