Wikis have been around long enough that folks are starting to get used to the concept—derived from the Hawaiian word wiki wiki, which means quick, wikis are Web pages that can be edited and added to from within the browser window itself, while you're viewing the page.

Wiki pages tend to have a very simple layout—bold, italic, maybe a horizontal line or two—but just being able to pop up to the web, click Edit, make change, then click Save is a big deal for many Web users. (Some wiki sites even allow you to e-mail something to the wiki page and have it added or appended automatically.)

This ease-of-editing makes wiki-hosting sites a common option for low-rent "groupware" applications—sort of the web equivalent of a chalkboard—where participants can read, add to and change an outline or notes for a given project or group of projects. For instance, a recent entry to this market, called JotSpot (http://www.jot.com), features an attractive interface and special wiki "applications" that enable you to track customers and clients, add forums, polls and more to your site. It's a promising, flexible use of wikis for gathering and managing organizational data.

But where JotSpot is able to do some complex things with a hosted wiki, BackPack (http://www.backpackit.com)—a service from the same company that makes the complex project-management site, BaseCamp—is deceptively personal. BackPack's claim to fame is its simplicity; once you're logged in, it's a single click to create a new page and start typing your content. BackPack helps make those pages more useful with tools for building tables or checklists. Plus, you can add memos by e-mailing them to a special address set up for each page, or you can attach images, documents and more to your pages.

The real secret, though, is that you can selectively publish a page on the Internet—or keep it private. What's more, private pages can mean only you can see it, or you can invite only certain guests can see it. In other works, BackPack can be used for personal organization, project management, electronic invitations, party organizing, checklists, memory scrapbooks—or all of those things individually and at once.

This "wiki" is extremely simple, very clever and flexible—if you give it a chance, you'll learn tons of ways to keep things online that keep you productive for work, school or life. The base level (five pages, 10 reminders) is free, with the first paid level starting at $5 per month.

One testimonial on the BackPack page says, simply, "I want to marry it." I don't feel that strongly about it, but I do hope to make the service a close friend.