thickeners

[parsnip]

I'm having a little trouble figuring out what thickeners to use for what. Here are the ones I know of:

psyllium (ground and soaked, or just soaked?)
flax
Irish moss/carrageen moss
agar agar (I know it's seaweed... don't know if it's raw, or if it's easy to find)
lecithin (not raw)
cashews
chia seeds

I know Irish moss is often used in raw pies.... what would be appropriate for thickening salad dressings?

I googled Irish moss -- that's quite an impressive list of alternate names for it, down near the bottom of the page!

Thanks!

[parsnip]

Sorry, meant to include the link: http://en.wikipedia.org/wiki/Chondrus_crispus

[NYbutterfly]

Avocado is a great thickener for soups...