Ion and Ion 2 are graphics adapters made by NVidia specifically for Atom based netbooks and nettops. They can be found in netbooks such as the Asus Eee 1201N, Lenovo S12 and HP Mini 311.
Ion generally has the performance of a GeForce 9400M, which while not being the best is certainly better than the Intel GMA options.
Ion Netbooks: http://www.newegg.com/Product/ProductList.aspx?Submit=ENE&N=2034940772+1725049759&QksAutoSuggestion=&ShowDeactivatedMark=False&Configurator=&Subcategory=772&description=&Ntk=&CFG=&SpeTabStoreType=&srchInDesc=
Ion from NVidia: http://www.nvidia.com/object/sff_ion.html