Difference Between Hd Flip Mino And Hd Ultra 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 hd flip mino and hd ultra

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!