[TYPO3-shop] Review or poll function for each product?

[Marco Fang]

Hello!

I'm studying tt_product functions recently, and the client wants some 
functions that tt_products doesn't have (or I don't know if it exists).
Is there any comment, product review or poll functions available with 
tt_products?

What I mean is the review system like eBay "Questions from other 
members" section of the single product view.
Or some functions attached to each single product which can let members 
to add product review, comments, poll for that product, sort like these.

Any comment or answer would help me a lot!

Marco Fang