Evernote is the service. It lets you take notes and keep track of lists, documents, all kinds of stuff on virtually any device you own. There are apps for the desktop, iOS devices, Android and clippers, plugins, and add-ons for most browsers.
Penultimate is a handwriting app. It lets you make simple and complex notes and keeps them all...yup, you guessed it. Right in your EverNote Notebooks.
The last item sort of speaks for itself. It's Contacts management tool.
Three tools and 1 Service that let you remember it all.