I really like the way some organisations have used the Google calendar as a way of communicating with their users, for example to manage opening hours. It wouldn't be logical to implement one in my organisation, however - our OPAC (Heritage) has a built in calendar as does our student portal (Moodle) - and between staff we use Outlook for our personal calendars and for a shared LRC calendar. One of the tools I really like on my Outlook calendar is the tasks. I enter every job/task/bit of work I need to do on it, assign it a priority and a to be competed by date. Previously I used to have a Word document containing my 'to do' list but I found that I was forgetting to update it. Using Outlook means by task list is open all the time and I can easily manage it by amending the status to completed when a job is done. The archive then allows me to record all my work for use in reviews - brilliant!
I also really like the idea of Evernote although I'm not sure it's a tool I would use very requently, maybe more for when I'm researching something. UPDATE: just found a brilliant use for Evernote, albeit it not work-related at all - collating things I've seen for my wedding!