I saw this awesome way to make a pop up card like an exploding box that you can actually mail which would make a great gift for someone. I made two of them for Valentine's for two people close to me. You could do this for birthdays, etc. One thing I did not realize is that the two pieces that go across in the middle inside have to be up towards the top. Otherwise your items won't stick up high like they should. You do have to close it after each time you place something on to see if it's sticking too far out the sides. Also, if you use a flower embellishment, it would definitely needs to be hand stamped at the post office as it'll make it bulky. The 'white piece' they reference in the video is for you to write your message on. I opted not to do so on mine as I had the message in the pop out pieces and the people I was giving it to knew who it was from. Below is the link to the youtube video I used and also the blog I saw it originally on.
I have another one in the works that is just a hello type one that I'll post up when it get's done eventually. :)