Is methyl cellulose edible?
Methylcellulose is commonly used in molecular gastronomy to raise the freezing temperture of solids and liquids. Think piping-hot ice cream.

For the gel, you could use agarose (commonly agar) to create a jelly.

The other obvious choice for the gel would be gelatin. Buy plain gelatin at the store and have at it with the directions.

You can create a foam using either the gelatin or the agar and an N2O whipper. This is also called an espuma.

The third, more fun choice would be to get thee to an asian food store and buy and flavor some tapioca pearls.