Show their wives and girlfriends this book you had custom made for your wife for Valentine's day...
There are like 50 pages of stuff like that in the book. The website let you build the faces, so I was able to get stuff close to what we actually looked like, which was also cool.
A few years ago I made something like this for Mr. Z, chronicling his first year as a dad (but with more photos). He still says it's one of his favorite gifts.