Internet experiments made a comeback during 2004. Here are some of the year's notable Web innovations:
Gmail -- Google rolled out a bunch of experiments, including a widely praised desktop search program and this initially controversial e-mail service. Gmail (gmail.google.com) raised the hackles of privacy advocates because it displays text ads targeted to the contents of your inbox. Google said it offers a trade-off of 1 gigabyte of free mail storage in return for those ads, which appear alongside, not inside, messages and are matched up by software, not people. At year-end, Gmail was still available only via invitation -- but other Web-mail services, such as Yahoo and Hotmail, had already upped their storage quotas to compete.
A9.com -- Among the ton of new Web search services that went live last year was a free, personalized one from an Amazon.com subsidiary. A9 (http://www.a9.com/) lets people store and query their own Web browsing and search histories, choose from a variety of ways to view search results and keep notes about what they see online in a personal diary.
Blinkx -- A start-up called Blinkx launched two new services, a free desktop search program (http://www.blinkx.com/) and the BlinkxTV video-search engine (http://www.blinkx.tv/). The former service takes a novel approach to searching: It infers what people are looking for from the documents they have open on their computers, not just keywords they type in a search box. The latter service captures video and audio from Web sites, then uses special software to index those clips and make them searchable.
Kayak.com -- This new virtual travel agent (http://www.kayak.com/) is giving such veteran travel search services as TravelZoo and SideStep a run for their money in helping people compare prices. Kayak lets people simultaneously search more than 60 travel Web sites and show prices for hundreds of airlines and thousands of hotels, while offering thoughtful ways to sort through its results.
Skype -- Internet telephone service pioneer Skype Technologies (http://www.skype.com/) launched a service in July, SkypeOut, that let users of the company's software call any phone line in the world at rates mostly under 2 cents a minute. (Previously, Skype worked only between computers equipped with its software.)
JibJab -- Animated political cartoons created by two Los Angeles brothers brought bipartisan comic relief to the polarized presidential election. More than 10 million people visited their site (http://www.jibjab.com/) in July to watch cartoon versions of President Bush and challenger John Kerry stoop to humorous name-calling -- "You're a right-wing nut job;" "You've got more waffles than a house of pancakes" -- to the tune of Woody Guthrie's "This Land Is Your Land."
FundRace 2004 -- An experiment at presenting public data in new ways, FundRace lets visitors enter any street address and see what people nearby contributed to presidential candidates in the 2004 election. The site (http://www.fundrace.org/) relies on reports that campaigns file with the Federal Election Commission.
Flickr -- Flickr (http://www.flickr.com/) was one of many innovative photo-sharing sites that popped up last year, encouraging social action around images. Flickr not only makes it easy to post photos online from cell phones and e-mail, it also gives people interesting ways to display, annotate and tag images to locate them later. The free service limits storage to three groupings of photos, while a $41.77-a-year plan offers unlimited storage.
Pac-Manhattan -- A real-life version of the Pac-Man video game was played out last spring (http://www.pacmanhattan.com/) on the streets of Manhattan by New York University students clad in ghost-like costumes. A handful of "generals" directed them around Greenwich Village via cell phones and tracked their movements on computers as they chased a player decked out as Pac-Man's dot-munching hero (advised by another "general").
E-mail Leslie Walker at firstname.lastname@example.org.