Amazon Kindle

I'm so primitive I note when I start and finish books in a separate Google calendar.

It's manual, but it makes it so simple to answer questions like "What did I read last summer?" or "When did I read x?". And in theory I could use the API to go through and find things started "Start: title by author" where there is no "Finished: title".

I have a lot of Google calendars, I use calendars for things that people don't think about... I have others that store logs of every phone call I've ever made, or films seen at the cinema. It's basically my version of a diary, but filterable, searchable.

this is a good idea. do you use your phone to fill them in or are you at a keyboard so often that you can do it that way?

I get very frustrated trying to use google voice to create calendar entries. Siri beats it hands down in this.