Where can you write and save memos on the droid? Things like account numbers, user names, passwords, etc.
The best note program I've found is EverNote!
It's in beta, not yet on the market. Go here to read about it.
What's great about EverNote is, you install an app on your PC or Mac, and you can now easily copy text from the internet or email by simply highlighting it, then tapping on an EverNote icon which the program adds to your browser! The highlighted text will be added to your EverNote account, which you can now view by downloading and installing the EverNote Android beta software!
It also let's you take voice recording notes, and even photos! Take a photo of something with text in it, and the search function in Evernote even searches text WITHIN the photo!
Another good app is 3banana. Create a 3bananna account on the internet, download the app from the Market, and you can easily enter text on your PC or Mac, and it'll automatically appear in your Android 3bananna program! Or, type a note on your Android device in 3bananna, and you can always view it from your PC!