Here's something creative that will be appreciated and you will have fun doing:
Make up a crossword puzzle and have all the hints be personal inside moments and jokes that only you two would know about. Put it on a poster board and add some clipart and some pictures to it!
The crossword puzzle could be time consuming and a bit frustrating ... you could do the same idea with a WORDSEARCH or WORDFIND puzzle.
Put your computer skills to work! Use Excel, get clipart from Yahoo Images Search, copy them, and reformat them, use a gluestick to put on posterboard.
Use graph paper, and pictures from magazines if you are not as good on the computer, and it will give it a homemade feeling.