I only have 128 varieties to keep track of. I made an Excel spreadsheet with information from the AHS website. I turned the spreadsheet into an html document which is part of my DL website. I have the website backed up on a CD and an external drive and on a server. I use metal markers, but no map except in my head. A huge tree fell on one of my beds in December. I'm sure all my markers are squashed under it. Can't stress about it until my DH gets that monster removed. Then I can have my fit!
The Plantstep program sounds interesting. I wonder if it's available for Macintosh.