Since I worked from home yesterday I was able to implement this idea while Kristian was out hunting with his dad. I took 35 colored index cards (35 for the age he was turning) and on one side I wrote "I Love You Because..." and on the back side wrote one of the 35 reasons why I love him. I then taped them all over the house for him to find when he got home.
I tried to put the card in a place that corresponded with what the card said. For example on Hunters bedroom door I taped that I loved him because he made me a mommy. On the microwave I taped that I loved him because he always cooks such great meals. Etc.
When he got home he had so much fun finding and reading all the cards. He even took a break at one point because he wanted to spread it out for longer. One thing I should point out is that Kristian really doesn't like greeting cards, he thinks they are a waste of money, you read them and then throw them away (actually I keep mine and have shoeboxes full of greeting cards I've received). He said that this was SO much better than getting a store bought greeting card and it's the sweetest birthday gift he's ever gotten. He was still talking about it today.
In addition to the cards I bought him a cake (we still don't have a working kitchen so I couldn't bake him one) and we ordered take out Chinese Food. Nothing exciting but he said between hunting with his dad and what I did for him he had a great day.