Brett , the 637 is the one I took with me last month to China and left it there , it does the lot plus more infact I would say we used only about 10 of its many functions and just plug it in at the nearest powerpoint for an o/nite recharge , having a normal keyboard makes it so simple even a dumbo like me had no hassles , , but the earlier non- colour version last year worked just as well , but not so many features , regards Robert .