Science Buddies: "Ask an Expert"

I'm doing a project on what mixtures makes for an effective lava lamp.
I know I can use water and oil, oil and vinegar but what else can I use

Check this out:

http://home.howstuffworks.com/question36.htm

http://www.oozinggoo.com/howto.html

FYI, I used Google to search for the query: how to make a "lava lamp"

Shijun