Hey Bruce -
I was a heavy "Memo Pad" user on the BB as well. My solution on Android was an app called "AK Notepad". The functionality is pretty similar, and it will alphabetize your notes the way Memo Pad did.
As others have stated, the biggest problem is syncing your old notes over. I couldn't find an easy way around this. I basically opened a new Word document in Google Documents, cut and pasted all of my old Memos from Outlook Notes (where they synced before I stopped using my BB), then opened GDocs on my Android, opened the same Word document, and had to cut and paste the data into new notes on AK Notepad.
Took me longer than it probably should have, but I got it all transferred, and now I use AK the same way I used Notepad.
As far as security, there is an online sync with a service called Snaptic if you don't want to house your notes on your SD card. Now that I'm thinking about it, I probably could have pasted my notes from Outlook into Snaptic, and then synced... ugh! Oh, well, all done now!