I was pretty comfortable with this exploration of sundry tools because, for once, I was encountering techs and tools that I've already been familiar with--either the ones listed, or very similar equivalent applications.
The biggest one is Google Calendar. Never have I utilized a more useful app; never has one become more ubiquitous to my daily life. I've been using it for about two or three years now and I just have it up on my browser constantly; I put in my class assignments, trips, visitors and visits. I also stick in things I aspire to do but it maybe gets bumped due to timing issues--so it just clicked-and-dragged to the next week or month. (Visiting my LIS friend Jared at the music library for a look around has been a frequent casualty due to my 506 class on Thursdays--no hard feelings, though ;-)) But it's great--I never forget anything, even those hole-in-the-wall art gallery exhibits or two-for-the-price-of-one zoo admission days.
Another utility that has been of great benefit to me is the whole concept of the online to-do list. Before this web 2.0 business, my life was drowning in bits of paper. Story ideas, books to read, song lyrics i heard on the radio in hopes of tracking the artist down later...no good. Certainly not for a future librarian! Then I found www.gubb.net. You can make as many little post-it note-resembling list things in different as you want, and specify whether you want them to be to-do style--with check boxes--or simply list style. No more paper drown. Sorry, backpack.com etc....looks like you have pay shields. Gubb is free. I love my Gubb!