There are an array of 3DTV technologies and you won't be able to make glasses that work with all of them, well not unless you are McGuyver. The easiest and cheapest way to get yourself set up in 3D land, so you can view what the industry calls the "anaglyph method", is to make yourself a set of 3D glasses like you probably remember as a kid.
Using these you'll be able to watch 3D YouTube videos, read comic books, look at 3D images on Flickr and best of all, watch Jaws IV in 3D.
For this you will need:
- A pair of cheap sunglasses
- Some transparent film
- A blue permanent marker
- A red permanent marker
- A pair of scissors
- An adult present
Take the cheap sunglasses, which no doubt make you look like you are an extra from Miami Vice, and pop out the lenses.
Once you've got the lenses out and hopefully haven't cut yourself doing so (we take no responsibility you hear), use the lenses as a template to create a new pair of lenses on the transparent film. For the best effect you could buy coloured transparent film to save you colouring, or you could opt for some clingwrap but then you'll really look like a douchebag.
Once you've got your drawn-out lens shapes colour them in. Doing it now means you can reach the edges without getting permanent marker over your fingers as you can go over the edges. Sharpie or Magic marker are good makes. Make sure you work the pen over the area quickly to avoid streaking and dry marks. The right lens should be Blue, the left lens red.
Cut out your new lenses. If you aren't comfortable with sharp objects (you know what happened last time) then ask a grown-up.
Place the new lenses into the frames and there you have it. You can now look at anaglyph images.
Alternatives and hints
1. If you can't be bothered to butcher a pair of sunglasses you could always make a pair of glasses from cardboard.
2. If you can't even be bothered with making a pair of glasses grab a CD case, draw a line down the middle. Colour the left half red and the right half blue
3. When you butcher your sunglasses don't throw the lenses away. If you own a DSLR you can combine them with a lens cap to make a filter to create interesting effects for your photography.
4. Failing all of the above you could just buy a pair of 3D glasses. A quick hunt around the Internet should allow you to find them for as little as 20p.