Well, you've covered a lot of options.
A really easy way to backup some files and make them available to your PC(s) is Dropbox. First 2GB is free.
If you want a more traditional "backup" solution, Titanium Backup is awesome (Pro is best, but I think you need to have your phone rooted). Also ES File Explorer has a lot of these functions, including mounting network drives, etc.
Good Luck!
-AJ