Do some selfies at places she will know in years to come: city and local landmarks, places and things that interest you, not just the local playground where you and she have been.
Digital pics have a date/time stamp, but any printed pics in a book should have a date written on the back and under.
You will be thought about regularly, but make sure that it is always a good memory you are leaving.
Your interests and accomplishments may be of interest to any men in her life; they will more naturally associate with those, so have something to say about your 'man' interests.
Geek credibility: do the Geek Code, and add 'extensions'. http://en.wikipedia.org/wiki/G...
Explain a man's understanding of love. Link it to how your lady and you got together. Add how you and she decided to have a child. She will need to understand this in order to get a rounded idea of how to choose a man in her life.
(Assuming you can) Write some HTML in a small text file that says some of the important "Dad things" things in a browser. Suggest that she can have this as a remembrance. If she runs it, okay. If not, she'll remember it anyway. Your collective 'geek' will be passed on.