o know which World Wide Web sites Martin Kessel deems important is to know Martin Kessel himself. That he lives in Natick (www.natick.com). That he owns a second home on Cape Cod (www.town.falmouth.ma.us). That he's a parent (www.lionking.org). That's he's Jewish (www.yiddishbookcenter.com). That he's a Democrat (www.senate.gov/
kennedy/). That he's interested in genealogy (www.rootsweb.com), in folk music (www.folkmusic.org), and in knowing when it might be wise to pack an umbrella (www.boston.com/weather/).
''That's definitely me,'' says Kessel, a 51-year-old vocational instructor, as he contemplates the more than 500 Internet ''bookmarks'' he's compiled on his home computer over the past half-dozen years. ''It's clear I'm not frivolous or flaky. I'm a serious person.''
Peeking at someone's bookmarks - those pointers to specific Web sites that a person considers worthy of a return visit - is the latter-day version of perusing someone's book collection or sifting through someone's stash of CDs. True, bookmarks aren't quite so public, although more people than you may think actually publish them on their personal Web pages. (Look! It's me! I'm into sugar-packet collecting and poems about cheese!) But if an anonymous 20th-century nutritionist can pronounce that we are what we eat, surely 21st-century Web surfers can proclaim that they are what they bookmark.
Actually, bookmarks are ''bookmarks'' only on Netscape Web browsers. They're ''favorites'' on Microsoft's Internet Explorer browser, and ''favorites places'' to America Online subscribers. But because Netscape Communications Corp. developed the first widely popular browser, in 1995, ''bookmarks'' have become the Kleenex of the genre. This is so despite the fact that the Internet concept of bookmarks was born two years earlier on the first graphical browser, known as Mosaic, wherein users could compile a ''hotlist'' of frequently visited Web sites.
By whatever name we call them, however, bookmarks can reveal everything from someone's fervor for Johann Sebastian Bach (www.jsbach.org) to someone else's devotion to lawn-mower racing (www.letsmow.com).
''Basically, my list reveals my personality.'' So declares Vladimir Prevot, 16, a Roslindale 11th-grader. Prevot's well-honed stash of a dozen or so bookmarks includes the Original Hip-Hop Lyrics Archive (www.ohhla.com), the Cisco Network Academy Program (http://cisco.netacad.net), and the fantasy football site Small World (www.smallworld.com). ''Music, technology, sports,'' Prevot says. ''The big three. That's pretty much what I'm interested in.''
Sandra Sheehan, a 27-year-old sales administrator who lives in Brighton, can point to a list of about 40 bookmarks and proclaim that, for better or worse, some represent passions she's reluctant to give up.
''There's at least one (www.do
sado.com) from what you might call my Western Square Dancing Period,'' Sheehan explains. ''I gave up the dancing but I've kept the bookmark. I think of it as kind of a historic document, like an old photograph.'' Sheehan's list also includes such current diversions as Ford Mustang automobiles (www.stangnet.com) and singer k. d. lang (www.kdlang.com). ''Know my bookmarks, know me,'' she says.
Prevot and Sheehan manage their bookmarks carefully, adding and subtracting with purpose and precision (which in itself tells us something about them). Their interests are clearly defined and easily deciphered. There are no unexpected turns, unless you count Sheehan's link to www.kick
boxing.com, a bookmark she describes as existing as the result of ''too much wine.''
But what about Virginia Brown of Maynard, a software developer whose bookmarks total more than 1,600? ''I guess it's gotten pretty big, hasn't it?'' Brown muses, sounding a tad apologetic. Indeed, hers is a well-ordered compendium - bookmarks can be arranged in categories - that scrolls on and on and on. It begins with staid professional sites dedicated to data communications and programming languages, moves through useful stuff such as investing information and weather sites, (''Everyone needs to know about the weather,'' Brown offers), and finally makes its way to several well-stuffed sections wherein we find Ginny Brown herself: flutist (www.flutenet.com), King Arthur fan (http://dc.smu.edu/
Arthuriana), movie buff (www.moviefone.com), photographer (www.shutterbug.net), sci-fi aficionado (www.sfsite.com), amateur astronomer (www.
eclipsechaser.com), student of archeology (www.archaeology.co.
uk), and faithful devotee of Monty Python (www.montypython.net).
Like a book collection, Brown's bookmarks change with her interests. ''Sometimes I trim, sometimes I build up new areas,'' she says. ''Lately I've been adding politics. The list really does reflect my interests.''
Some folks think so much of their bookmarks that they publish them in their entirety on their personal Web pages. On the JABarone Home Page - that would be the site of Joseph Barone, 41, a Pittsfield engineering manager - more than 1,000 bookmarks are neatly arranged in 47 categories. Barone updates them regularly, adding and subtracting from a collection that includes links to Chevy S-10 sites (www.s10-4x4.com), smoking sites (www.discountcigar
ettes.com), and singles sites (www.singles-on-line.com). ''The list is a resource that gives people places to go,'' Barone explains, ''but it also gives them a perspective on my life and my background.'' (People who post their bookmarks on their Web sites are quick to point out another advantage: They can access their own links from any computer with an Internet connection, not just their own.)
As windows onto the people who compile them, however, bookmarks ultimately have their limits. ''They can't tell you everything about someone, but they can certainly show you something of what that person values,'' says Kevin Skelly of Hadley, a tech support supervisor at the University of Massachusetts at Amherst whose list of more than 450 bookmarks runs from the Bible (www.bible.com) to the Official Women of Wrestling (www.owow.com). ''When you bookmark something, you're placing extra value on it. It's an indication, to some degree, of what makes you tick.''
But while bicycles and bicycling are one thing that makes Skelly tick, there are no bike bookmarks on his Internet browser. Why? ''I'm just not into the latest bicycles and the latest components,'' he explains. ''I try to maintain my bikes as cheaply as possible. I work on them myself, and I like to ride. For that, you just have to go out and do it. You can't simply click on it.''