Calendar and To-Do
Here's an easy one: Google Calendar is free and massively robust, and it integrates with Gmail. You can create as many separate calendars as you require, and you can share those calendars with anyone.
Although Google Calendar includes a task-list feature, it's too simple for our liking. We prefer Remember The Milk (free), which also plugs into Google Calendar, Gmail, and a bunch of other services. Remember The Milk's flexible design makes it great for everything from simple grocery lists to exhaustive Getting Things Done life management. For $25 a year, you also get to use RTM's excellent mobile apps for iPhone and Android.
If you want something more structured than Remember The Milk, Toodledo (free) is an excellent task and project management system. It integrates with a wide assortment of mobile apps for Android, iPhone, and iPad.
Bookmark and Password Sync
Several tools, plug-ins, and add-ons out there promise to help you keep your bookmarks and passwords in sync, but only one makes it onto our list. Xmarks (free, Premium upgrade $12 per year) synchronizes all your bookmarks and saved passwords among Internet Explorer, Firefox, Chrome, and Safari. It permits you to create distinct profiles so that you can have one set of bookmarks for home and another set for work, and you can change profiles on the fly. Xmarks is a must-have add-on for every Web user.
For most of the past decade, picking a search site was a no-brainer: Just use Google. (It was good enough for Yahoo.) Now Microsoft has made that choice a little more complicated, giving Google a serious run for its money with the introduction of Bing.
The two search giants have different strengths. For basic Web searches with instant results, Google (free) is still our top pick. And although our staff is divided on the question of image search, we still narrowly favor Google for pictures, too.
When you're searching for videos, though, it's hard to beat Bing (free). The search engine lays out results in an intuitive grid, and even plays instant clips as you hover over them with your mouse, so you know what you'll see before you click.
Beyond all the cute cat pictures and embarrassing celebrity videos, the great promise of the Internet has always been education. If you can pry your eyes away from the latest goofy diversion on YouTube, you'll find an unfathomable store of knowledge out there just waiting for you.
You probably already realize that Wikipedia (free) is the largest single repository of collected human knowledge. Although this publicly edited encyclopedia has garnered widespread criticism concerning a few high-profile acts of page vandalism, the site's content has generally come out on top when subjected to serious academic review.
When you're looking for fast facts on just about anything, bypass Google and Wikipedia and head straight for Wolfram Alpha (free). This reference site's unique algorithm constructs a quick information page on any subject you search for. Type in "Montana," for example, and the site will bring up a simple-to-read list of essential facts about the state's population and economy, complete with links to primary sources.
The next time someone forwards you another obnoxious chain e-mail, browse to Snopes.com and search for the message's subject line. The free Snopes.com is the essential source for digging up the truth behind the Internet's most prevalent hoaxes, scams, urban legends, and myths. If more people we knew went there, we'd spend a lot less time rolling our eyes.
What Wikipedia is to general knowledge, iFixit is to technology. The site bills itself as "the free repair manual that you can edit," but it's much better than that. iFixit is loaded with user-created how-to instructions for upgrades and repairs, and the site includes links to official user manuals for most tech products. And if you're really stumped about how to accomplish something, just ask your question, and the active community of tech experts will chime in to help you out.