I am an Apple guy...iPhone, iPad and Mac. Work supplies a desktop PC.
I use the apple calendar and sync it with gmail. For everything else I use Evernote. Evernote is available as an app and works well on both the iPhone and iPad and I can also use it on the desktop. I can't get things simpler than that.
For Evernote I use a lot of what http://www.thesecretweapon.org/ suggests.