I got a new book, Novelty Cards by Sue Nicholson, and in it was this folded Explosion Card. Using an 8x8 piece of paper you simply fold it and attach to the inside of the card. As the card is opened the folds 'explode' into the message.
The eyes have had glitter added to them to give them a little extra sparkle. I printed the heart, attached it to heavy paper and then attached it to a piece of mid weight cardboard and cut it out. If I had thought I should have inked the edges before adhering it to the card, but it was too late and too hard to do once it was attached (I used 2 pop up dots to attach and raise it off the card)
The Happy Face heart is from a kit Spellweaver made called Sweet Amore, the inside is actually a quickpage she had made in a kit called Be Mine. Spellweaver isn't selling her kits anymore so I'm afraid these things aren't available to you. The inside was actually bright red but I changed the hue/saturation to the blues.
This is how the card looks folded and closed
As it opens the inside, folded paper begins to open or explode
The more it opens the more the inner is revealed
Until you've got the whole thing open. I added the candy heart rubons and a brad and ribbon for a little extra.