As of April 5, 2006, a series known as Norisuta Hai began airing five minute Hamutaro episodes known as “Tottoko Hamutaro: Norisuta Hai!” The Norisuta Hai series is animated differently from the original series and appears to appeal to a younger audience. There does not seem to be any connection between Tottoko Hamutaro and Tottoko Hamutaro: Norisuta Haai beyond the slated appearance of all fifteen original ham hams.

Just to confirm, It airs as a part of a collection of series titled “Norisuta Hai!” 「のりスタ　は～い！」 produced by Shopro Japan (Shogakukan Productions). And By the way, according to the Japanese edition of Wikipedia, it’s titled “Tottoku Hamutaro Hai~!” without the “Norisuta” as mentioned in the English edition.

Related Links:
Wikipedia: Hamtaro
Wikipedia Japan: Tottoku Hamutaro [Japanese]
Cynthia BBS: The final episode and “Hamutaro Hai!” screenshots [Japanese] [Beware, Video files posted suspected to be spywares]
Hatena: Tottoku Hamutaro [Japanese]
Official web sites:
Official Japanese web site
Official English web site
TV Tokyo’s official Tottoku Hamutaro home page (the old series)
TV Tokyo’s official “Norisuta” home page
ShoPro official “Norisuta” home page