Tools I Use: What Technology Makes Your Life Easier?

Sometimes, like when I'm just about to go to sleep and I suddenly remember that I have an email to respond to, and now, no matter how much I tell myself it can wait until morning, I won't sleep unless I get up and take care of it, I get frustrated by all of the technology around me. But, all in all, I think that there's a lot of technology tools that I use that really do make my life easier to manage. Here are my favorite tools:

1. The ZipList iPhone App- This app (and its accompanying website) allows me to clip recipes from different internet sites (or type in my own) and then click on the meals I want to make and add the ingredients to a master grocery list. That list is shared with my husband, so we never again have to end up with two gallons of milk and no eggs. It is also much less likely that we will both forget our phones on joint grocery ventures than it is that we will both forget a handwritten list. Plus, the list is organized by store section, so I've done much less sprinting to the back to pick up something we forgot.
2. PDF X-Change- This is a free program that allows me to make notes on PDF's. It's invaluable when I'm doing research for a paper. I am a very active reader, and I have to be able to underline, highlight, and make notes in the margins in order to fully engage with what I'm reading. This makes it easy to save everything in an electronic format. It saves paper, takes up less space, and I can still read my typed notes six months later (which isn't always true of stuff I've sprawled sideways in the margins of printed articles).
3. XMind- This is another free download. I've started using this mind mapping program as my default for planning projects or brainstorming for papers. I take notes from books in it, complete with page numbers, so that I can just copy and paste it directly into the paper as I compose later. It allows you to make connections between ideas, add notes and symbols, and work in a less linear format.
4. Google Calendar- Though this is certainly no secret, I don't know how I would function without it, so I'd feel remiss if I didn't mention it. I use it for home, work, and class, and I have created different individual calendars for each role so that I can see all, some, or just one of them at a time.

What about you? What technology keeps your world running (relatively) smoothly?