Difference Between Mino Hd And Ultra Hd Flip Mino HD 2nd Gen VS Flip Ultra HD, Whats The Difference?

Flip Mino HD 2nd Gen VS Flip Ultra HD, whats the difference? - difference between mino hd and ultra hd

http://www.amazon.com/exec/obidos/tg/detail/-/B0023B14TK/ref=ord_cart_shr?_encoding=UTF8&m=ATVPDKIKX0DER&v=glance

http://www.amazon.com/Flip-Camcorder-Generation-Minutes-Brushed/dp/B002R5AM7C/ref=pd_cp_p_2

What is the difference between these 2 camcorders?

Is it worth it?

Thank you!