The very best data logging app I have ever come across (and I have tried quite a few) is mySugr. They are promising a ‘droid version for you iPhobes, but it is currently available in the App store for fruit-based phone/iPod/iPad owners. Excellent data input/handling/search(yay!)/reporting/averaging (inc copious notes and tagging if you like that sort of thing, even TBR %/duration etc for pumpers) and a quirky sense of humour that even manages to make logging kinda fun. Hard to believe I know!