I use two.
GDocs Notepad is a simple tool that syncs all your notes with a folder in your Google Docs account. If you have 20 notes in GDocs Notepad, then you'll have 20 documents in a folder in Google Docs. You can edit a note in one place and it will appear on the other after you sync. Unfortunately, there's no tagging or folders on the Droid side so lots of notes tend to get muddled together, and there's no text formatting (bold, italics, etc). You can search through your Google Docs for text with an app called Power Search, but it takes some time to search online.
OI Notepad is also very simple, and it has two advantages: 1. You can tag notes and then look at all your notes with virtual folders, which makes organizing hundreds of notes possible, and 2. notes in OI Notepad are searchable via the normal Android search function very quickly, or via Power Search. OI Notepad has a nice import and export function - I was able to transfer a few hundred memos from my Palm device into it easily - but it doesn't sync with anything.
Both are free, and I use both.
I use GDocs Notepad for memos that tend to be long "documents," or for memos that I will want to edit on a real computer (Via Google Docs) from time to time.
I use OI Notepad for smaller bits of text that want to have handy at all times, and that I will want to find later via Search.
For example, the furnace filter sizes I need when I go to Home Depot every few months go into OI Notepad. Lists of consulting checks I deposit go into GDocs Notepad.
Hope this helps,
Warr
