I used my LG U990 which comes with the built in ability to record anything in slow motion given a high level of light.
NOTE: With all slow motion captures, lighting is CRITICAL. If the lighting is not bright enough or the wrong colour, you will end up with a very blurry or fuzzy appearance of your video (this is demonstrated towards the end of this video).
First: Get your hands on a second hand LGU990 or similar phone that has high FPS (frames per second) ability.
NOTE: 20-25fps is what video usually runs at, any lower than this and it looks 'jumpy' to the eye.
Secondly Find a location that has great natural light or use a light source that is within a natural colour range. (this stops your video looking stodgy and brown.)
Thirdly: Videotape your self doing whatever you want and make sure it is being saved to the memory card of the phone.
Plug the microSD card into your reader and copy the contents to your local storage area (user folder/desktop/finder/explorer/wherever).
NOTE:if you have a Mac you cannot view these videos without VLC (free video player) or a codec for quicktime (i use flip4mac) as it is not a Mac standard codec (or windows for that matter)... so install these now. [FOR PC ,USE SOMETHING LIKE 'K-LITE CODEC PACK' TO GET WINDOWS MEDIA PLAYER TO VIEW THESE OR JUST INSTALL ONE OF THE THOUSANDS OF OTHER PLAYERS THAT CAN PLAY IT.]
Once you have all your video footage taken, use a video editing suite of your choosing to compile them and add a little zing.
Upload to instructables or youtube, vimeo, dailymotion etc... and share with your friends to make them smile (or cringe)