Molecular gastronomy is one of those vague terms that you hear. It could really mean just about anything though. It's essentially transforming food chemically or physically into something that it wouldn't normally be. That leaves the door wide open. This could mean freezing things with liquid nitrogen, turning liquids into jelly orbs, or making bricks of meat with meat glue.
Realistically, in a home kitchen, there's not much use for those type of preparations. In addition to being costly and often time intensive, sometimes it can be downright dangerous. Luckily, there are some relatively simple techniques that you can use in your own kitchen that won't result in you accidentally freezing yourself into frostbite.
The easiest technique to accomplish in a home kitchen is foam made with soy lecithin. You can mix it into just about any liquid, then use an immersion blender with a whisk attachment. You'll get a light airy foam, and the bubbles are much more stable so they don't pop.
Another way to easily modify the physical state of almost any liquid is gelification. Just add a bit of agar agar. It's a tasteless, odorless seaweed powder that turns your liquids to solids. It's almost like gelatin, except there isn't any horse hooves in it. That alone makes it more appetizing, right?
But where could you find a bunch of supplies that would let you do some reasonably not scary molecular gastronomy? Any number of places. Where could you find all of the tools in one place for certain? Molecule-R. You can order directly from the website, and they include a DVD that demonstrates some recipes too. The kit provides you with multiple samples so you can practice. Your final results will be the talk of your dinner party, and add interesting texture to your dishes.