Most mail services (i.e. GMail, GoDaddy, etc) support a "Note" feature.
First you need to enable Notes in your "Mail, Contacts, Calendars" settings for the email service you prefer. Then on your Windows PC, use a mail client (such as Thunderbird or Outlook) and you should be able to access your Notes there. Alternatively, you can use the webmail interface for whatever email account you chose
I use Notes on three different services...1) iCloud for personal-related notes 2) Gmail for school-related notes 3)GoDaddy for work-related notes
Each service organizes and stores Notes differently. For example...Gmail creates a "Label" for Notes. Just play around and you'll figure out how your service organizes the Notes.
When you compose Note on your iPod Touch (or whatever iDevice you have)...just be sure to look at which account you are creating the Note the under.
Hope that helps! Sorry for the long post, but I literally just explained all of this to my mother who has TONS of Notes on several different accounts.