A birthday card made for a friend who is a Pokemon fan, or at least has played Pokemon Platinum and realises the existence of Pokemon BW. I think there are very few people over the age of 20 who actually are like this (myself excluded), so I decided to keep his card Pokemon-themed.
The mechanism for this card is relatively simple; as you pull the tab, the image in the TV window changes. If you want to try it out for yourself, you can check out this nifty site
which even links to a template to get you started.
This card was quick and fun to make (I think I finished it under 2 hours). The measurements to ensure that images slid over each other neatly without overlapping were a bit tricky, but I'm pleased at how neat the card turned out (and on the first try!)