I would like to access a user's Google Plus One history
With +1 enabled, the history is saved in your Google profile and optionally can be displayed:
http://www.google.com/+1/button/
It is possible to access this programatically (once the user has given permission via normal Google Authentication and Authorization?)
I have only been able to find information for the API to add the button to sites.
You can allways try to parse the data used by G+ itself.
The G+ user profile has a tab with all public +1, that can be fetched with
https://plus.google.com/_/plusone/get?oid=<google-plus-id>
It seems to be related to JSON, but with some differences.
Check this out....
Dave, I'm not sure about a user's history, but the count for particular URL is available via a JSON-RPC service (https://clients6.google.com/rpc). Here's a little post on how to: http://www.johndyer.name/post/Getting-Counts-Twitter-Links-Facebook-Likes-Shares-and-Google-Plus-One-Buttons.aspx
I'm guessing that same service can get additional data, but I can't find any public documentation either.
